LIST OF CONTRIBUTORS. 



ANGLE, EDWARD H., M.D., D.D.S. ; 

CAPON, W. A., D.D.S. ; 

CASE, CALVIN S., M.D., D.D.S.; 

CRENSHAW, WILLIAM, D.D.S.; 

CRYER, M. H„ M.D., D.D.S.; 

DARBY, EDWIN T., M.D., D.D..S. ; 

GODDARD, C. L., D.D.S. ; 

GUILFORD, S. H., A.M., D.D.S., Ph.D.: 

INGLIS, OTTO E., M.D., D.D.S.; 

JACK, LOUIS, D.D.S.; 

KIRK, EDWARD C, D.D.S., Sc.D. ; 

NOYES, FREDERICK B., B.A., D.D.S. ; 

OTTOFY, LOUIS, D.D.S.; 

PRINZ, HERMANN, M.D., D.D.S.; 

THOMPSON, ALTON HOWARD, D.D.S. 

TRUMAN, JAMES, D.D.S., LL.D. ; 

WARD, MARCUS L., D.D.Sc. ; 

WEEKS, THOMAS E., D.D.S. . 



THE 



AMERICAN TEXT-BOOK 



OF 



OPERATIVE DENTISTRY 



IN CONTRIBUTIONS BY EMINENT AUTHORITIES. 



EDITED BY 

EDWARD ('. KIRK, D.D.S., Sc.D., 

Professor of Dental Pathology, Therapeutics, and Materia Mbdica, and Dean of the 

Dental Department of the Universiti oj Pennsylvania, Philadelphia; Editor of 

"The Dental Cosmos;" Officieh de l'AcadEmie de France. 



FOURTH EDITION, REVISED AND ENLARGED. 



ILLUSTRATED WITH 1015 ENGRAVINGS. 




LEA & FEBIGEE, 
PHILADELPHIA AND NEW YORK. 

1911 






V 



Entered according to Act of Congress in the year 1911, by 
LEA & FEBIGER, 
the Office of the Librarian of Congress at Washington. All rights reserved, 






CI. A 2 9582 8 



WITH THE CONSENT OF THE CONTRIBUTORS 

THIS BOOK 18 DEDICATED TO 

JAMES TRUMAN, D. D. S., L.L. D., 

THE CHARACTERISTIC OF WHOSE LONG PROFESSIONAL CAREER HAS 
BEEN THE [NCULCATION OF THE PRINCIPLES DPON 

WHICH THE WORK 1> HAS ED. 



PREFACE 



The demand for a new edition of the American Text-book of Operative 
Dentistry has necessitated much more than a mere revision of the 
previous text. The work has been largely rewritten, and the fourth 
edition is therefore practically a new book. Such a radical change 
has been rendered necessary by the rapid evolution which has taken 
place throughout the entire domain of the science and art of dentistry 
since the publication of the previous edition. The accumulation of 
new data, the investigation of the deeper problems of dental science, 
and the modification exerted by these factors upon the practice of 
dentistry have wrought changes that in certain departments are little 
less than revolutionary. So rapid and far-reaching in their effects are 
many of the changes which have taken place that the whole subject of 
operative dentistry has been and still is in a state of flux. 

The mirroring of the progressive movement in operative dentistry 
will be evident in the plan as well as in the text of this work. The 
subject of cavity preparation is treated as a teehnic procedure, first, 
because it can be most intelligently comprehended as such, and 
further, because the work is primarily intended for the instruction of 
the undergraduate student. It is fully recognized that the scientific 
basis of such subjects as pyorrhea alveola ris, tooth discoloration, tooth 
extraction, root-canal treatment, orthodontia, etc., is much more fully 
elaborated in the present work than would be justifiable in a treatise 
or text-book devoted exclusively to operative dentistry as an art; but 
as there still appears to be a demand upon the part of students for a 
volume furnishing a comprehensive view of the fundamental principles 
upon which alone an intelligent and rational practice may be based, 
the treatment of the subject of operative dentistry in the present work 
has been extended to include those principles. 

Certain differences of opinion will be occasionally manifest in the 
work in the treatment of allied subjects by different authors. While 
such differences are, of course, not desirable in a work intended for the 
use of untrained students, and while no conflict of opinion will be 
noticed with respect to established scientific principles, it is manifestly 
impossible to secure unanimity upon subjects which have not as yet 

(vii) 



Vlll PREFACE 

reached a stage of development entitling them to classification among 
the exact sciences. For example, the unsettled question whether under 
any circumstances extraction is a justifiable operation in connection 
with the correction of malocclusion, has led to differences of opinion 
that are not at present reconcilable, and cannot be until a larger body 
of evidence based upon observation and experience has been submitted 
at the bar of professional judgment. 

The Editor takes this occasion to express his deep sense of appre- 
ciation of the uniform courtesy and spirit of helpfulness which have 
characterized the attitude of all of his collaborators in this work, for 
their patience under his suggestions, and their willingness to sacrifice 
personal interests to the thoroughness and accuracy of the work as a 
whole. To the publishers his thanks are due for their unhesitating 
cooperation in every effort which tended to the completeness of the 
work in all its phases, and he is likewise under obligation to his 
colleague, Dr. Riethmuller, for the preparation of the accurate and 
copious index. 

The Editor assumes personal responsibility for the nomenclature used 
throughout, and in submitting the volume to the critical consideration 
of his fellow-teachers and his larger circle of fellow-students he can 
hope for it no more generous treatment, nor, indeed, could he expect 
more, than has been so freely accorded to its predecessors. 

E. C. K. 

University of Pennsylvania, 1911. 



LIST OF CONTRIBUTORS 



EDWARD H. ANGLE, M.D., D.D.S., 

President of the Angle School of Orthodontia, New London, Conn. 

W. A. CAPON, D.D.S., 

Lecturer on Dental Ceramics in the. University of Pennsylvania, Philadelphia. 

CALVIN S. CASE, M.D., D.D.S., 

Professor of Orthodontia, Chicago College of Dental Surgery, Chicago, 111. 

WILLIAM CRENSHAW, D.D.S., 

Dean and Professor of Operative Dentistry and Dental Pathology, Atlanta 
Dental College, Atlanta. 

M. H. CRYER, M.D., D.D.S., 

Professor of Oral Surgery in the Dental Department of the University of 

Pennsylvania, Philadelphia. 

EDWIN T. DARBY, M.D., D.D.S., 

Professor of Operative Dentistry and Dental Histology in the University of 
Pennsylvania, Philadelphia. 

C. L. GODDARD, D.D.S., 

Late Professor of Orthodont la, University of California, College of Dent 1st ry, 
San Francisco, Cal. 

S. H. GUILFORD, A.M., D.D.S., Ph.D., 

Professor of Operative and Prosthetic Dentistry and Dean of the Philadel- 
phia Dental College, Philadelphia. 

OTTO E. INGLIS, M.D., D.D.S., 

Professor of Dental Pathology and Therapeutics in the Philadelphia Dental 
College, Philadelphia. 

LOUIS JACK, D.D.S., 

Philadelphia. 

EDWARD C. KIRK, D.D.S., Sc.D., 

Professor of Dental Pathology, Therapeutics, and Materia Medica, and Dean 
of the Department of Dentistry in the University of Pennsylvania, Phila- 
delphia; OfRcier de l'Academie de France. 

FREDERICK B. NOYES, B.A., D.D.S., 

Professor of Dental Histology in the Northwestern University Dental School, 
Chicago, 111. 

LOUIS OTTOFY, D.D.S., 

Professor of Clinical Therapeutics, Chicago College of Dental Surgery- 
Chicago; Attending Dental Surgeon, St. Luke's Hospital, Manila, P. I. 

(ix) 



x LIST OF CONTRIBUTORS 

HERMANN PRINZ, M.D., D.D.S., 

Professor of Materia Medica, Therapeutics, and Pathology in the Washington 
University Dental School, St. Louis, Mo. 

ALTON HOWARD THOMPSON, D.D.S., 

Professor of Dental Anatomy, Kansas City Dental College, Kansas City, Mo. 

JAMES TRUMAN, D.D.S., LL.D., 

Emeritus Professor of Dental Pathology, Therapeutics, and Materia Medica 
in the University of Pennsylvania, Philadelphia. 

MARCUS L. WARD, D.D.Sc, 

Professor of Dental Physics and Chemistry in the University of Michigan, 
Ann Arbor, Mich. 

THOMAS E. WEEKS, D.D.S., 

Professor of Dental Anatomy, Operative Technique, and Clinical Dentistry 
in the Philadelphia Dental College, Philadelphia; Author of Weeks' 
Technique. 



CONTENTS 



CHAPTER I 

HUMAN ODONTOGRAPHY 17 

By Alton Howard Thompson, D.D.S. 

CHAPTER II 

DENTAL HISTOLOGY WITH REFERENCE TO OPERATIVE DEN- 
TISTRY 56 

By Frederick B. Notes, B.A., D.D.S. 

CHAPTER III 

ANTISEPSIS IN DENTISTRY 118 

\\\ James Truman, D.D.S., LL.D. 



CHAPTER IV 

EXAMINATION OF THE TEETH AND ORAL CAVITY PRELIMINARY 
TO OPERATION— REMOVAL OF DEPOSITS APPLIANCES AND 
METHODS RECORDING RESULTS L3S 



By S. II. Guilford, A.M., D.D.S., Ph.D. 



CHAPTER V 

CREATING INTERDENTAL SPACES PREPARATORY TO FILLING 
- GRADUAL SEPARATION — IMMEDIATE OR FORCIBLE 
SEPARATION 140 

By S. H. Guilford, A.M., D.D.S. , Ph.D. 



CHAPTER VI 

MODIFICATION OF DENTINAL SENSITIVITY BY DEHYDRATION 
— TOPICAL MEDICATION — ELECTRICAL OSMOSIS — GEN- 
ERAL ANESTHESIA 145 

By S. H. Guilford, A.M., D.D.S., Ph.D. 

(xi) 



xii CONTENTS 

CHAPTER VII 

TECHNIQUE OF CAVITY PREPARATION 153 

By Thomas E. Weeks, D.D.S. 



CHAPTER VIII 

EXCLUSION OF MOISTURE— EJECTION OF THE SALIVA— APPLI- 
CATION OF THE DAM IN SIMPLE CASES, AND IN SPECIAL 
CASES PRESENTING DIFFICULT COMPLICATIONS— NAPKINS 
AND OTHER METHODS FOR SECURING DRYNESS .... 191 

By Louis Jack, D.D.S. 



CHAPTER IX 

THE OPERATION OF FILLING CAVITIES WITH METALLIC FOILS 

AND THEIR SEVERAL MODIFICATIONS 201 

By Edwin T. Darby, D.D.S., M.D. 



CHAPTER X 

USE OF THE MATRIX IN FILLING OPERATIONS 235 

By William Crenshaw, D.D.S. 

CHAPTER XI 

PLASTICS 262 

By Marcus L. Ward, D.D.Sc. 

CHAPTER XII 

COMBINATION FILLINGS 324 

By Marcus L. Ward, D.D.Sc. 

CHAPTER XIII 

RESTORATION OF TEETH BY CEMENTED INLAYS 333 

By W. A. Capon, D.D.S. 

CHAPTER XIV 

THE TREATMENT AND FILLING OF ROOT CANALS .... 391 
By Otto E. Inglis, D.D.S. 



CONTENTS xiii 

CHAPTER XV 

PYORRHEA AT, VEOLARIS * . . 464 

By Edward C. Kirk, D.D.S., Sc.D. 

CHAPTER XVI 

DISCOLORED TEETH AND THEIR TREATMENT 519 

By Edward C. Kirk, D.D.S., Sc.D. 

CHAPTER XVII 

EXTRACTION OF TEETH 545 

By M. II. Cryer, M.I)., D.D.S. 

CHAPTER XVIII 

LOCAL ANESTHESIA 623 

By Herm \\\ Prinz, M.I)., D.D.S. 

CHAPTER XIX 

PLANTATION OF TEETH 646 

By Louis Ottofy, D.D.S. 

CHAPTER XX 

MANAGEMENT OF DECIDUOUS TEETH 664 

By Clark Goddard, A.M., D.D.S. 

CHAPTER XXI 
ORTHODONTIA 683 

By Edward II. Angle, M.D., D.D.S. 

CHAPTER XXII 

DENTO-FACIAL ORTHOPEDIA 873 

By Calvin S. Case, D.D.S., M.D. 

CHAPTER XXIII 

ORAL PROPHYLAXIS 910 

By S. H. Guilford, A.M., D.D.S., Ph.D. 



INTRO DTJCTORY. 



A STUDY of the advances which have of recent years taken place in 
the field of Operative Dentistry will reveal, besides the important addi- 
tions to onr knowledge in the shape of novel methods and improved 
technique, a vastly more Important advance manifested in a better and 
more general understanding of scientific principles, and the application 
of dental science to dental art, resulting in a more rational practice. 
Especially is this true in regard to the etiology of dental and oral 
pathological conditions, and the rationale of the modes of treatment 
indicated for the morbid states constantly confronting the dental 
practitioner. 

The modifications in surgical method- and the greatly improved 
results which are the outgrowth of modern scientific studies in bacterial 
pathology, while they have made a considerable impress upon dental 
operative method-, have not, however, received that universal practical 
acceptance among dental operator- which their immense importance 
demands. There is no field of special surgery in which the import- 
ance of exact knowledge with respect t<» aseptic and antiseptic treat- 
ment is more marked than in the practice of dentistry. The dental 
operator is continually confronted with septic condition-, so that pre- 
cise knowledge of their origin, causes, phenomena, and treatment are 
essentials to the legitimate practice of the profession. 

The performance of any operation, and especially those which are 
classified a- capital, with unclean hand- or infected instruments would 
in the present stage of surgical art be regarded a- criminal malpractice. 
It should be so considered in dentistry. The loss of a patient's life as 
the result of surgical septic infection is no longer permissible. Lack 
of antiseptic precautions in certain dental operations may directly lead 
to and as a matter of fact has been the cause of fatal results. It has 
been shown conclusively ' that a large variety of pathogenic micro- 
organisms are almost constant inhabitants of the oral cavity. In addi- 
tion to the numerous forms which bring about an acid reaction, there 
are many specific organisms which produce in inoculated animals 
pyemia and septicemia in their several clinical classes. But while the 
dental practitioner is not often called upon to face the issues of life 



1 W. D. Miller, Dental Cosmos, November, 1891. 



15 



1 6 INTR OD UCTOR Y. 

and death in the course of his work, his responsibilities as related to 
the issues with which he does deal demand of him the same care and 
thoroughness in order to attain the character of result which the pos- 
sibilities of modern dentistry require of him. In the following pages 
the importance of asepsis and antisepsis in dental operations is con- 
stantly impressed upon the mind of the student. 

By the term asepsis is specifically meant the condition under which 
are excluded those influences or causes which induce infection by patho- 
genic micro-organisms ; when a tissue or surface has been rendered 
germ-free it is said to be in an aseptic condition. By antisepsis is 
meant the means by which the septic state is combated or the aseptic 
state is attained. 

Under the aseptic condition repair of tissues takes place normally 
without interference, wounds and injuries heal with a minimum of dis- 
turbance, and the inflammatory concomitant is of the simple traumatic 
type, without suppuration or tendency to diffusion. 

The aseptic state, in many operations in the mouth, is not readily 
attainable and cannot be maintained for any length of time ; but in all 
operations which involve the pulp and pulp chamber, as well as the 
periapical region through the pulp canals of teeth, strict aseptic con- 
ditions, as regards external infection, are perfectly attainable through 
exclusion of the oral secretions by means of rubber dam, the use of 
suitable disinfectants, and sterilized instruments. It is the class of 
operations here alluded to which are most prolific of disturbance from 
infective inflammations caused by ignorant or careless manipulation. 

The time is at hand, if indeed it has not already arrived, when puru- 
lent inflammations following dental treatment will be regarded with 
the same condemnation by the dentist as by the general surgeon. The 
operative section of this work is written in full recognition of the prin- 
ciples here indicated. 



OPERATIVE DENTISTRY 



CHAPTER I 

HUMAN ODONTOGRAPHY 
By ALTON HOWARD THOMPSON, D.D.S. 

The teeth are located at the portal of the alimentary system of the 
animal organism. They help to differentiate in the choice of the elements 
of nutrition and reduce these elements to digestible condition. The dental 
armament is, therefore, the first and chief factor in the mechanism of 
alimentation. The teeth are, morphologically, transformed tissues 
belonging to the tegumentary system of animals, and are hard, calcareous 
bodies, situated in the oral cavity at the anterior orifice of the alimentary 
canal. In the lower vertebrates they may be scattered over all of the 
bones and cartilages surrounding the mouth, but in the mammals, as in 
man, they are confined to the upper and lower jaws only. The name 
teeth, is therefore, in the latter, especially applied to those structures 
located in the oral cavity which contain a calcified tissue known as 
dentine. 

The main function of the teeth is the prehension and mechanical sub- 
division and reduction of substances employed for food, preparatory 
to digestion. The main divisions of this function are: (1) Prehension, 
or the seizing of food substances; I 2) division, or cutting into pieces; (3) 
mastication, or comminution into small particles, and (4) insalivation, or 
the mixing of food with the oral secretions. For the performance of these 
various functions, different forms of teeth are developed in different 
animals in great variety. For the office of prehension, long trenchant 
canines are developed in lower mammals, but in man these teeth are 
reduced to the level of the other teeth. Division and cutting are per- 
formed by the incisors, which are well developed in man. Crushing and 
mastication are performed by the premolars and molars, which in man 
are much reduced and modified, owing to his omnivorous diet. The 
denture of man is midway between the extreme form of the carnivora, on 
the one hand, and herbivora, on the other. Food selection has reduced 
the denture of man to a simple type, which is quite primitive, showing 
evidences of reversion. The functions of the teeth in man being less 
2 (17) 



18 HUMAN ODONTOGRAPHY 

specialized than in lower, highly specialized animals, his denture 
is correspondingly reduced, function being here, as ever, the cause and 
sustainer of structure. 

The primitive tooth form is that of the simple cone. This is still found 
in the teeth of fishes, reptiles, and some lower mammals. The more 
complicated teeth of the higher mammals have been formed by the 
modification of the single cone. Thus the incisors and canines are com- 
posed of single cones, the bicuspids of two cones fused together, and the 
molars are formed of three or more cones arranged to form triangular 
or quadrangular crowns. In the genesis of tooth forms, therefore, the 
complex teeth, as the bicuspids and molars, are formed by the repetition 
and addition of cones and their accompanying cusps, both laterally and 
longitudinally of the jaw. The transition from single to complex teeth 
is accomplished by the repetition of the single cone in various directions. 
Thus a bicuspid is formed by the evolution of a cingule upon the lingual 
side of the buccal cone, which gradually develops into a lingual cone with 
cusp and root, as illustrated in the double cone shape of the upper first 
bicuspid of man. The upper molar crown is developed as follows: The 
primitive simple cone, the primordial element, is called the protocone. 
The first cone (Fig. 1, A) and the first step in molar formation is the 
growth of cusps upon the mesial and distal aspects of the protocone (Fig. 
1, B). The mesial cusp is called the paracone and the distal the metacone. 
This gives three cusps in a mesio-distal line, forming a three-coned 
crown called the triconodont type. This is the type of the early forms 
of the mammalian molar teeth, and is still preserved in some of the car- 
nivora, seals, lemures, etc. The next stage is the shifting of the cones so 
as to alter their relative positions to form a triangle (Fig. 1, C). In the 
upper jaw the protocone moves to the lingual side and becomes the mesio- 
lingual cusp, leaving the paracone as the mesio-buccal cusp and the 
metacone as the disto-buccal cusp, which come together on the buccal 
side, thus forming the trigon of the upper molar. This is the trituber- 
cular crown of early geological times from which all other molar types 
were developed, and is still preserved in the opossum, some insectivora, 
and some other modern mammals. In the lower molars the primitive 
cone is called the protoconid, but it moves to the buccal side and becomes 
the mesio-buccal cusp. The paraconid has been aborted in man, so that 
the metaconid becomes the mesio-lingual cusp, which forms the trigonid 
of the lower molar crown. Thus the triangles of the upper and lower 
molars alternate — the apex of the upper molar being directed lingually 
and the lower bucally, so that they pass each other with a shear-like 
motion. The next stage in the evolution of the molar crowns is the addi- 
tion to the trigon of the upper molar on its disto-lingual face, of a heel, 
or talon (Fig. 1, D), which supports the fourth cusp, the hypocone, which 
strikes into the centre of the trigonid of the lower molar, like a pestle into 
a mortar. Then there is added to the trigonid of the lower molar on its 



THE DENTAL ARCH 



19 



distal side, a heel, or talonid, which supports two or three cusps — the 
buccal, which is called the hypoconid; the disto-buccal, the hypoconu- 
lid; and the disto-lingual, the entocouid. Sometimes there is developed 
on the lingual face of the upper molar a fifth cusp which is called the 
hypoconule. This is the counterpart of the fifth cusp of the lower molar, 
the hypoconulid. This is the phylogenetic history of the molars in man, 
which are quite primitive in type, but their evolution can be readily 
traced in beautiful completeness. 



O 



Fig. 1 

o o o 




W V] iv vi (v V] 



VqVqV 




The phylogenetic history of the molar cusps: .1, the single cone, the reptilian stage; B, lower 
mammals, the triconodont crown; C, the tri tubercular molar , the trigonodont crown; D, the quadri- 
tubercular molar crown. 



The Dental Arch. — The teeth of man are arranged around the margins 
of the upper and lower jaws in close contact, and have no interspaces 
between them. The basal arch is a graceful parabolic curve, with some 
variations which lead from the round arch to the incomplete parallel- 
ogram or even to a well-defined V-shape. These variations may be 
classified as follows: 

First: The Square Areh (Fig. 2, a). This is found usually in persons 
of strong osseous organization, of Scotch or Irish descent — i. e., of Gaelic 
extraction — and is probably derived in the first instance from a doli- 
chocephalic people. The squareness is more or less dependent upon the 
prominence of the large canines, which stand out very markedly at the 



20 



HUMAN ODONTOGRAPHY 



angles of the square. The incisors present a flat front and project slightly, 
with little or no curve of the incisive line. The bicuspids and molars 
fall backward from the canines with no perceptible curve. The two 
sides are quite parallel, but sometimes there may be a slight divergence 
toward the cheek at the rear. This is the low form of arch which appears 
in the apes and some low races. 

Second: The Rounded Square (Fig. 2, b). This is the medium arch, 
and is the form usually met with in ordinary, well-developed, robust 
Americans. The canines seem to be only sufficiently prominent to give 
character to the arch without a resemblance to the arches of the lower 
animals. The incisors are vertical and the line curves slightly from 
one canine to the other. The bicuspid-and-molar line curves slightly 
outward from the canine and converges at the rear. 



Fig. 2 




Square. 



Rounded Square. Rounded. 

The main types of the dental arch. 




Rounded V 



Third: The Rounded Arch (Fig. 2, c). This is the circular or " horse- 
shoe" arch. It is nearly semicircular, the ends curving inward at the 
rear, the outlines of the arch tracing a decided horseshoe shape. The 
canines are reduced to the level of the arch, so that there is no prominence 
of these teeth. The bicuspids and molars follow the line of the curve. 
This arch is quite characteristic in some races, as the brachycephalic 
South Germans. 

Fourth: The Rounded V (Fig. 2, d). In this form the round arch is 
constricted in front or narrowed so that the incisors mark a small curve 
whose apex is the centre. It is the arch of beauty, and is that most 
admired in women of the Latin races. 

These are but the basal forms of the dental arch. Ordinarily, modi- 
fications of these types occur in all degrees ; it is the variations, the com- 
posites, which are most met with. 

The Occlusion of the Teeth. — The upper teeth describe the segment 
of a circle larger than that of the lower teeth; so that the edges of 
the anterior teeth above close over those below, and the buccal cusps 
of the grinding teeth above close outside of the buccal cusps of the lower 
teeth (Fig. 3). By this arrangement the buccal cusps of the lower 
grinders are received into the depressions or sulci between the buccal 
and lingual rows of the cusps and tubercles of the superior molars and 



THE OCCLUSION OF THE TEETH 



21 



bicuspids, and the lingual cusps of the upper grinders are received into 
the sulci of the lower grinders. By this arrangement the whole of the 
morsal surfaces of these teeth are brought into contact in the several 
movements of mastication, thereby rendering the performance of this 
function more effective. 

Then, again, the upper incisors usually close over the lower for one- 
third of their length. This allows of the shearing action by which the 
incisive function is performed as the edges of these teeth are drawn past 
each other. 

The line of the horizon of occlusion (Fig. 4, A to B) presents a decided 
curve from front to rear, of greater or less degree in different forms 
of the arch. Thus it is high at the incisors, curving downward at the 
bicuspids, reaching its lowest point at the first molar; it curves upward 



Fig. 3 



Fig. 4 




Incisors. Bicuspids. Molars. 

The relative position of the upper and 
lower teeth in occlusion. 



The horizon of the line of occlusion and plane of 
occlusion. 



rapidly at the second molar, and is highest again at the third. In 
the round arch the plane is more flattened and exhibits the extreme 
downward curve in the square arch. Between these extremes there 
is, of course, every variety of modification. The form of the plane of 
occlusion is shown in Fig. 4, C. 

The tendency of the bolus of food is toward the lowest part of the 
curve at the region of the lower first molar, so that the extraction of 
this tooth always affects the performance of mastication. 

In the apposition of the teeth of the opposite jaws the mechanical 
arrangement is such that the dynamics of mastication is subserved 
and the greatest effectiveness secured (Fig. 5). Thus the morsal sur- 
face of the upper central incisor is opposed to all of that of the central 
incisor below and to the mesial half of the lateral; the upper lateral 



22 



HUMAN ODONTOGRAPHY 



opposes the distal half of the lateral below and the mesial face of the 
canine; the upper canine, the distal half of the face of the lower canine 
and the mesial half of the first bicuspid ; the upper first bicuspid opposes 
the distal half of the lower first bicuspid and the mesial half of the second; 
the upper second bicuspid opposes the distal half of the lower second 
bicuspid and part of the lower first molar; the upper first molar opposes 
the distal part of the lower first molar and the mesial half of the second; 
the upper second molar opposes the distal half of the lower second and 
part of the third; and the upper third covers the remainder of the lower 
third molar. 



Fig. 5 




The apposition of the upper and lower teeth. 

By this method of apposition the teeth are so arranged that two teeth 
receive the impact of half of two of the opposite jaw, thus distributing 
the force of occlusion and insuring the safety and strength of the teeth. 
This ''break- joint" arrangement permits each tooth to bear two oppos- 
ing ones, and also helps to preserve the alignment. Then again if one 
tooth be lost the opposing teeth still rest against two teeth, one at each 
side of the space. The normal condition of the articulation is rarely 
preserved, however, as mutilation usually disturbs it; the teeth move on 
account of the force of occlusion, and effective mastication is more or 
less destroyed. 

Number and Classes of the Teeth. — Man has thirty-two teeth, divided 
into four classes, viz.: (1) Incisors; (2) canines, or cuspids; (3) pre- 
molars, or bicuspids; and (4) molars (Fig. 6). This is expressed by the 
dental formula as follows: 



.9 2 1 

i. - — , c. — 
2 — 2 1 



1 9 9 



m. 



3 — 3 



32. 



THE INCISORS 



23 



1. The incisors are eight in number, four above and four below — 
two on each side of the median line. The two next to the median line 
are called the central incisors, the ones next to them distally the lateral 
incisors. 

2. The canines, or cuspids, are four in number, two above and two 
below — one on each side immediately approximating the lateral incisor 
on the distal side. 

3. The premolars, or bicuspids, are eight in number, four above and 
four below — two on each side approximating the cuspids on the distal 
side. The first of these next the cuspid is called the first bicuspid, the one 
next to it on the distal side the second bicuspid. The same designation 
applies to both upper and lower bicuspids. 



Fig. 6 




Incisors. Canines or Premolars or Molars, 

cuspids. Bicuspids. 
The classes of the teeth, comprising the left half of a full denture. 

4. The molars are twelve in number, three on each side of each jaw, 
approximating the second bicuspid on the distal side. The molar next to 
the second bicuspid, both above and below, is called the first molar; the 
next one distally is called the second molar; the next one distally, and the 
last tooth in the jaw, is called the third molar, or " wisdom tooth" (dens 
sapiential). 

Functionally, the incisors are formed for cutting, as their name im- 
plies; the cuspids for prehension and tearing (for which purpose this 
tooth in lower animal forms is often excessively developed). It also 
serves in guiding the bite. The bicuspids are the crushing teeth, and 
the molars are formed for grinding, triturating, and insalivating the food. 

The Incisors. — The function of cutting and dividing food is per- 
formed by various organs throughout the animal kingdom, and even 



24 HUMAN ODONTOGRAPHY 

cutting teeth are found very low down in the scale of life. The cephalo- 
pods have cutting teeth on the odontophore; the insects, some worms, as 
the leech and other low forms, cut by means of sharp or saw-edged man- 
dibles; in the sea urchins true incisor teeth are found which simulate the 
incisors of rodents. The fishes and reptiles have no true incisors. How- 
ever, in the fish sarcjus, incisor-like teeth are found, and the turtles have 
the jaws sheathed in a horny covering with sharp edges. Some aberrant 
fossil reptiles have cutting teeth also, but these are exceptions to the rule. 
The lowest mammals are deficient in cutting teeth, but have simple 
conical teeth in all positions in the mouth, like the reptiles. The her- 
bivora have highly developed incisors in all species. In the carnivora the 
incisors are much reduced, as their function is usurped by the premolars, 
which have long blades for cutting flesh. In the quadrumana the human 
type of incisor appears and develops progressively from the lemurs to 
the higher apes, in whom the human type is well developed. 

The Upper Central Incisor. — This is the first tooth in the dental series 
in man. It is situated in the front of the mouth, next to the centre of the 
arch, which is the mesial border of the intermaxillary bone. In adult 
man these bones fuse with the anterior borders of the right and left 
superior maxillary bones. Their junction with each other marks the 
centre of the dental arch. 

The general form is that of a truncated cone with its top flattened out 
to form the cutting edge. 

The form of the crown is spade-like, or a compressed-wedge shape, 
the edge being quite thin and the thickness increasing rapidly to the 
base. It is slightly bent toward the lingual side, or much curled over in 
some cases. 

The labial face is imperfectly square or oblong, the cervical margin 
being rounded (Fig. 10, a). It is convex from side to side, but only 
slightly so from cervix to edge. Two shallow depressions or furrows 
extend the length of the face perpendicularly (b), dividing it into thirds, 
called lobes — the mesial, (c), median (d), and distal lobes (e). These 
furrows and lobes are quite conspicuous when the tooth is erupted, but 
are abraded by age and the wear of use and dentifrices, until the face 
becomes smooth. The mesial margin is a little longer than the distal, so 
that the cutting edges slope upward toward the distal side (/). 

The lingual face is smaller than the labial, being on the inner and 
smaller curve of the crown, and is narrower from side to side (Fig. 7). 
It is triangular in outline, being wide at the edge and narrow and rounded 
at the base or cervix. The marginal ridges (a) are high and conspicuous, 
and extend from the basal ridge to the edge on the mesial and distal mar- 
gins of this surface. The basal ridge (b) is a strong elevation continuous 
with the marginal ridges at the base of the crown. It is sometimes 
developed into a raised cusp, the ridge at the base of which forms a cingu- 
lum. A ridge or lobe (c) extends from the basal ridge to the centre of the 



THE UPPER CENTRAL INCISOR 



25 



edge, uniting with the median lobe from the labial face to form the 
median tubercle. A depression or fossa (d) is found on each side of the 
median lobe between it and the marginal ridges, or, when the lobe is low 
or entirely absent, these fossae may be continuous. A fault, or fissure, at 
its junction with the basal ridge frequently forms the seat of caries. 

The mesial face (Fig. 8) is a rather long triangle in shape, with a 
concaved base at the cervix of the tooth (a) and a long point toward the 
edge. It is nearly straight in a longitudinal direction, but rounded and 
convex transversely. It is longer than the distal face, the edge descend- 
ing in that direction. The enamel line dips downward into this face, and 
there is a depression above it (b) which sometimes extends upward on the 
root. The point of contact with the opposing tooth is near the cutting 
edge. 

Fig. 7 Fig. 8 

b 

,d 





Diagram of the lingual face of the upper 
central incisor. 



Mesial. Distal. 
The mesial and distal faces and edge of the 
upper central incisor. 



The distal face is also triangular in outline (Fig. 8), but it is more 
curved in the longitudinal axis, so that this surface is convex in all direc- 
tions. It is most curved in the transverse direction. The enamel dips 
downward into the surface {(f), as in the mesial, but there is not so much 
of a depression above this line. The point of contact is one-third of the 
distance from the angle (e). 

The edge, or morsal margin, of the crown is formed by the compression 
of the top of the truncated primitive cone. It is quite wide and square 
except at the distal corner, which is rounded. The angle with the mesial 
face is acute ( Fig. 8, /). When the tooth is first erupted, the ed^e has 
three prominent tubercles {(/), which correspond to the ridges on the 
labial and lingual faces. These are soon worn off with use, so that the 
ed^e usually looks straight. The pitch of the edge is toward the median 
line. 

The mechanical structure of the crown is a matter of importance. It 
will be observed that it consists of several elements: first, a broad cutting 
blade (Fig. 9, a) supported by two strong lateral columns (b) on each 
side, and that these columns are upheld by two strong marginal ridges 
(c) leading up from the lower ridge (d). These ridges are buttresses 
which guy and uphold the columns which contain and carry the blade. 
Hence, when these ridges are destroyed by caries or in operating the 
support of the column is lost and the blade readily breaks away. 



26 



HUMAN ODONTOGRAPHY 



In operations upon this tooth, this blade-like structure must be con- 
stantly borne in mind, for weakening of the elements of the crown may 
easily result from excessive cutting. The columns of support can be better 
preserved with the inlay filling than with pressure fillings which require 
more strength of walls. Less cutting away is required, and the contour 
can be better preserved and supported by the inlay and cement. A 
better esthetic effect is also thereby obtained. Small cavities in these 
teeth are, of course, better filled with pressure gold fillings, but larger 
ones are better treated by fillings with porcelain inlays, care being taken 
to preserve as much tooth substance as possible, to attain the best artis- 
tic and mechanical results. Fragile enamel margins should not be 
retained, of course, but when backed by dentine the walls should be 
preserved — especially when parts of the supporting columns of the 



crown. 



Fig. 9 





The mechanical design of the crown of the 
upper central incisor: a, the blade; b, the two 
columns supporting the blade; c, the marginal 
ridges acting as guys, bracing the columns; 
d, the basal ridge at the base of attachment 
for the guys. 



Diagram of the labial face of the upper 
central incisor. 



The neck of the central incisor is a rounded pear-shape in outline, 
the labial half being wider (Fig. 11, a) than the lingual. There is not 
much constriction of the tooth at the neck. The enamel edge curves 
upward on the root on the labial and lingual sides, and dips downward 
on the mesial and distal faces. It terminates abruptly on all sides, 
especially on the lingual, where a considerable ridge is sometimes raised 
(Fig. 10, c). 

The root is cone-shaped and tapering (Fig. 11, b). The rounded pear- 
shaped section continues almost to the end. 

The pulp chamber is spacious and open, and of the general form of 
the tooth (a and c). The radical portion of the canal gives free access, 
but the flattened coronal portion is difficult to cleanse. In young teeth 
the cornua or horns of the pulp may project far toward the angles (c). 

The Lateral Incisor. — This tooth approximates the central incisor on 
its distal side, and is also implanted in the intermaxillary bone. It is 
of similar spade-like form and of the same architectural design as the 



THE LATERAL INCISOR 



27 



central, modified by the distal half being more rounded in every direc- 
tion. As the crown is narrower than the central, the destruction of the 
marginal ridges on the lingual face weakens the edge still more, so that 
it breaks off more easily. The crown is narrower in the mesio-distal 
diameter than the central, but, still almost as wide labio-lingually, the 
relative difference of thickness in the two directions is more apparent. 
The tooth has the appearance of being compressed mesio-distally. The 
thickness increases rapidly from the edge to the neck (Fig. 12, B). 



Fig. 11 



Fig. 12 




a b c 

The root of the upper central incisor. 




B C D 

The upper lateral incisor. 



The labial face (Fig. 12, C) is more rounded than that of the central. 
It is half incisor and half cuspid (a), the mesial half toward the central 
incisor resembling that tooth (b), and the distal half toward the cuspid 
resembling it (c). The mesial angle of the edge is quite acute, while the 
distal angle is rounded and obtuse. The three lobes may be well devel- 
oped, similar to those on the central incisor, but 
are usually indistinct, although the central ridge 
is prominent. 

The lingual face (Fig. 12, D) is much de- 
pressed, but less concave than that of the central 
incisor. The marginal (<7) and basal ridges (e) are 
quite prominent. The basal ridge is often raised 
into a permanent cingule or talon, an exaggerated 
example of which is shown in Fig. 13, which is a 
revival of the basal talon found in the apes — and 
the insectivora. This cingule occurs more fre- 
quently on the lateral incisor than on any other 
of the anterior teeth. The depression above it is 
often the location of a fault, a fissure or pit, which 
becomes the seat of caries. The basal ridge is 

sometimes cut by a fissure which leads down quite upon the neck of 
the tooth (Fig. 12, /). Sometimes the entire surface is full and rounded 
without any concavity whatever. 

The mesial face (g) is of triangular form similar to that of the central 
incisor. It is rounded toward the edge labio-lingually, but flattened at 
the neck, with a depression at the enamel line which leads upward upon 




Showing unusual devel- 
opment of the cingule or 
basal talon on an incisor. 
( From case reported by Dr. 
W. H. Mitchell, Dental 
Cosmos, vol. xxxiv. p. 
1036.) 



28 HUMAN ODONTOGRAPHY 

the root. The labial angle is sometimes the seat of a depression (h), 
which gives the angle a hook shape. The depression varies in width and 
depth, and may become the seat of caries. The point of contact with 
the central incisor is at the junction of the lower with the middle third 
of the length of the face. 

The distal face is more convex in all directions, and resembles the 
canine in form, being in harmony with the general form of the distal 
half of that tooth. From cervix to edge it is rounded and the contact 
eminence in the middle third is very full (i). From this point it rounds 
off rapidly to the edge. The upper third is depressed rapidly toward 
the cervix, with a considerable depression at the enamel line leading 
off to the distal groove on the root. 

The edge is divided into two portions by the prominent tubercle (;') 
in the middle which terminates the prominent central ridge of the labial 
face. The mesial half is straight, like that of the central. When worn, 
these features disappear and the edge becomes almost straight. The 
pitch of the edge, like that of the central, is toward the median line. 

The same mechanical structure of the crown is found in the lateral 
as in the central, except that the crown is more slender and weaker, so 
more precaution must be observed to prevent breaking during and 
after operating upon it. 

The neck is much flattened mesio-distally, and is of a compressed 
pear shape, or flattened oval on section. The enamel margin pursues 
the same course as on the central incisor, rounding upward tqw T ard the 
root on the labial and lingual sides and dipping downward on the distal 
and mesial. It does not terminate so abruptly as that of the central 
incisor, and presents less of a ridge at the gingival margin. 

The root is commonly longer than that of the central incisor, is nar- 
rower, flattened mesio-distally (Fig. 12, A, B). It tapers gradually, not 
rapidly like the root of the central incisor. It is a flattened oval on 
section (E). Sometimes there is a hook at the end, curved distally. 
Grooves sometimes occur on the mesial and distal sides. 

The pulp canal is flattened in conformity to the shape of the root, 
but is readily entered if the root be straight. 

The lateral incisor is very irregular as to form, presenting various 
degrees of deformity or abnormality, and may sometimes be reduced to 
a mere peg. It is also erratic as to eruption, being sometimes suppressed, 
not appearing for several generations of a family. It follows the third 
molar in the frequency of its irregularities both as to form and frequency 
of non-eruption. 

The third incisor of the primitive typal mammal sometimes reappears 
in man, and is known as a supernumerary. It rarely assumes the proper 
incisor form and position in the arch, but usually erupts within the 
arch, and is a mere pointed peg-shaped tooth. 




THE LOWER INCISORS 29 

The Lower Incisors. — These are most conveniently described as a group, 
as they are very similar in form, having but slight variations between 
the central and lateral incisors to be noted. 

They are located in the anterior portion of the lower jaw, upon each 
side of the median line, opposite the incisors above. Their function is 
the same as that of the upper incisors, the cutting of food, which they 
perform by opposing the upper. The lower central opposes only the 
central above; the lateral, both the upper central and lateral incisors. 

The lower central incisor is the smallest tooth in the dental series. It 
is of spade-like form (Fig. 14), the crown being a double wedge shape 
(a, b). The first wedge (a) is observed 
on viewing the crown from the front, 
the widest portion being at the morsal 
edge and the point at the cervix. The 
second wedge is observed from the 
side (6), the widest part being at the 
neck and the point at the morsal edge 
of the crown. The edge is thin, but 

the labio-lingual diameter increases The lower incisor, 

rapidly to the cervix, which is the 

widest part. The crown is widest mesio-distally at the edge, but dimin- 
ishes to the neck, which is scarcely more than half the width of the edge. 
The tooth cone is therefore compressed in one direction at the edge, 
and in another at the cervix. The mechanical elements are the same 
as those of the upper central, but with the parts less strongl) marked. 

The labial face is a long wedge shape (a), the widest part at the ed^v 
and narrowing to the cervix. It is usually straight, or nearly so, longi- 
tudinally, and straight across the vd^v. but round and convex at the 
neck and the cervical half. Sometimes vertical ridges are found on these 
teeth when they are first erupted, but these soon wear off. 

The lingual face is depressed and concave from edge to cervix in, 
but less so from side to side. The marginal ridges are often well marked. 
In the lateral incisor the fossa is often more marked and the marginal 
ridges more distinct. 

The mesial and distal sides are of wedge-like form, straight from edge 
to cervix and widening in the same direction. A depression runs across 
the neck just above the enamel line. 

The neck is much compressed disto-mesially, and the root partakes 
of this flattening through its entire length. The section presents a 
compressed oval (e), The enamel line dips downward on the labial and 
lingual sides, and curves upward on the mesial and distal in a manner 
characteristic of the incisors. 

The edge is perfectly straight from side to side, after the three tuber- 
cles, found when first erupted, are worn off. 

The root is flattened like the neck, and frequently a groove runs the 



30 HUMAN ODONTOGRAPHY 

entire length on the mesial and distal sides. Occasionally complete 
bifurcation results, which recalls the form of this tooth found in lower 
animals. 

The pulp canal (e) is of similar form to the root, and is flattened and 
thin, so that it is often difficult to effect an entrance to it with instru- 
ments. 

The lateral incisor is similar in form to the central incisor, but is wider 
at the edge, and the distal corner of the edge is slightly rounded (d). In 
all other features it resembles the central incisor. 

The canine, or cuspid, appears very early in the history of vertebrate 
life in its prototype, the single conical tooth of fishes and reptiles. The 
conical form of the canine is maintained down through all the suc- 
ceeding stages to man, with mere variations as to contour, as manifested 
in the higher vertebrates. It is the tooth of prehension from the lowest 
to the highest forms. As prehension is the most primitive of tooth func- 
tions, so the conical, canine tooth is the primitive tooth. In the higher 
mammals it is probably modified from the premolar series, as it is the 
first tooth posterior to the intermaxillary suture. In the lower mammals 
it is variously modified, but it is in the carnivora that it attains its 
highest specialization. Its greatest development was found in the 
extinct felidse, where it was long and sabre-shaped, with sharp 
serrated edges, as in the cave lion and bear and the fossil forms of 
America. The living cats, the lion, tiger, leopard, etc., have the highest 
forms of this tooth, but it is reduced in the dogs and bears and other 
omnivorous forms. In the quadrumana the canines are well developed, 
and in the apes they are very large and strong, and are formidable weap- 
ons. Owing to the continued absence of the "missing link/' there is a 
sudden transition between the higher apes and man, as they are much 
reduced in the latter, being brought down to the level of the other teeth. 
Indeed, the canine presents more points of divergence from the form of 
this tooth in the anthropoid apes than any of the other teeth, all of which 
resemble those of the apes very closely. It is practically a crushing 
tooth in man as prehension is in abeyance as a human dental function. 

The Upper Cuspid. — This is the third tooth from the median line, 
and approximates the lateral incisor on its distal side. It is the first 
tooth posterior to the intermaxillary suture, and is embedded in 
the maxilla proper. It is commonly said to form the spring of the 
arch, and conveys the impression of great strength, as is indicated by 
its strong implantation. It is more strongly implanted, and by a longer 
and larger root, than any of the other teeth. Zoologically it is the largest 
tooth in the dental series, but in man is much reduced from its proto- 
type, the larger carnassial canine of lower animals, especially the car- 
nivora. It is the principal prehensile tooth, and is therefore first in 
order of function in the dental series. 

The crown has a spear-head shape (&), hence its name, cuspid, from 



THE UPPER CUSPID 



31 



the Latin cuspis, " point, pointed end." It is constructed essentially 
for piercing and tearing. The central cusp or point is braced in all 
directions; the edges leading up to it both mesially and distally (which 
serve for cutting as well), the strong labial ridge coming downward 
from the cervix (c) to the median ridge leading up on the lingual sur- 
face (d), all support it in the office of prehension and the laceration 
of flesh. 

The labial face (b) presents the outlines of the spear shape, more or 
less rounded in different cases. Starting from the well-defined cusp just 
in front of the central axis of the tooth, it widens sharply for about one- 
third of its length, whence it narrows gradually to the gum line, which 
is fully rounded. In some cases the mesial and distal angles are rounded 
and the outlines are more of a leaf shape (e). The surface is slightly 
rounded mesio-distally, so that the sides slope roundly or flatly away 
from the central ridge. This ridge descends from the middle of the 
cervical margin, curving slightly forward and then backward to the 



Fig. 15 




point of the cusp (c). This curve recalls the curving shape of this tooth 
in the felidse. It is usually a sharp, prominent ridge, but may be re- 
duced and rounded so as to be scarcely perceptible. The three lobes 
of the surface are imperfectly marked— the central ridge dominating 
and dwarfing the lateral ones. The lateral furrows on each side of 
the central ridge separating it from the lateral lobes are more or less 
marked, especially toward the edge. Wear reduces in time the promi- 
nence of the lobes and ridges and obliterates the furrows. 

The lingual face is of similar spear-shape (d), but is more flat. It is rarely 
concave. The thickness of the crown increases gradually to the lateral 
prominences, which gives a blade-like edge, then rapidly to the shoulder 
at the base. A strong vertical ridge extends from the cusp to the basal 
ridge (d), with a slight concave depression on each side. The basal 
ridge is well marked and sometimes develops into a cingule, more or less 
marked. The marginal ridges lead up on each side only so far as the 
lateral protuberances. They are not strongly marked as a rule. The 



32 HUMAN ODONTOGRAPHY 

fossae on each side of the vertical median ridge, between it and the mar- 
ginal ridges, may be quite deep, but are usually shallow and ill defined. 

The mesial face in outline is not unlike the central incisor, but its 
contour is very different, for it is more or less rounded in all directions, 
and the lateral eminence in the lesser third makes this part especially 
full (i). From this point the surface is depressed roundly to the enamel 
line at the neck, where a depression of greater or less depth is found. 
It is somewhat flattened at the cervix. The point of contact is at the 
eminence, which touches the lateral incisor. 

The distal face is of similar form to the mesial, except that it is more 
full and the eminence more pronounced, which gives the increased width 
of the crown on that side. The surface descends rapidly toward the neck 
and is rounded labio-lingually. The point of contact with the first 
bicuspid is on the lateral protuberance. 

The morsal edge presents a prominent cusp, which is almost central 
to the long axis of the tooth. The side facets slope away, but still retain 
their cutting edge (b). The distal side of the edge is longer than the 
mesial, by reason of the increased size of the distal protuberant angle. 
The sharp point is soon worn off to a rounded cusp, and, as wear increases 
with age, it may be reduced to a straight surface between the mesial 
and distal protuberances (g). 

The neck is a flattened oval on section, or the lateral direction of the 
labial portion may be greater than that of the lingual (/t). The enamel 
line preserves the same curves as on the incisors, i. e., rounding upward 
on the labial and lingual surfaces and dipping downward on the mesial 
and distal. The enamel terminates gradually with but a slight ridge, 
unless it should be on the lingual side. A depression occurs on both 
mesial and distal sides above the curve, which may lead up as a groove 
on the root. 

The root is longer than that of any other tooth, and it is at least one- 
third larger than that of the central incisor. It is of a rounded trihedral 
form, or irregularly conical. It is usually straight, and tapers to a 
slender point, which may be curved or very crooked. In well-arranged 
dentures, where it has erupted naturally, it is usually straight. 

The pulp canal is large and open, of the same form as the tooth, and 
easily entered. It is regularly formed except in those cases where the 
root is curved, and even in these it can be filled if not too crooked, as it 
is so open and accessible. 

The Lower Canine. — This is similar to the upper in form and outline, 
except that it is somewhat smaller, more slender, and more rounded in 
form (Fig. 16, a). It differs also in being more compressed mesio-distally 
and in being flattened in the neck and root. The crown leans backward 
on the root so that the mesial face is almost straight the entire length 
of root and crown. It forms the spring of the lower arch, and is strongly 
built to oppose the strong upper canine in the act of prehension and 



THE LOWER CANINE 



33 



Fig. 1( 



tearing. It opposes the mesial surface of the canine above and the distal 
surface of the upper lateral incisor. 

The labial face is a long oval (a), the cusp being blunt and the neck 
rounded while the mesial side (c) is flattened. The lobes are indistinct 
and the central ridge is rounded from side to side. The entire face is in- 
clined inward to accommodate the occlusion. The crown in many cases 
presents the appearance of being blunt toward the distal side. 

The lingual face (b) is flat, sometimes cup-shaped, and the marginal 
ridges are not prominent. The central ridge sometimes stands out 
strongly. The basal ridge is weak and is rarely developed into a cin- 
gule. The crown increases gradually in thickness from the point to the 
neck. 

The morsal surface presents a mere rounded eminence; the cusp may 
be sharp in childhood, but usually it is soon reduced by wear. Some- 
times it remains sharp and prominent. The lateral edges are not devel- 
oped, but are mere ridges lead- 
ing down to the lateral faces, 
which are not prominent, except 
the distal (d), which is often full. 

The mesial face is quite flat, 
and straight with that face of 
the root. The eminence is not 
marked. It is rounded only at 
the eminence, but flattened at 
the cervical third (c). 

The distal face has the most 
prominent eminence (d), the 

crown being bent in that direction. The cervical third of this face is flat. 
It descends rapidly from the eminence. 

The neck is usually oval (/), or, when compressed, spindle-shaped 
upon section (g), being depressed on the mesial and distal sides at the 
origin of the grooves running up on the root. The enamel line is not 
so variable as on the incisor, but more nearly on a level on all four 
aspects. 

The root is long, flattened, and tapering (a, b, c). It is shorter than 
that of the upper cuspid. It is grooved on the mesial and distal sides — 
so much so as to tend toward bifurcation. This, indeed, sometimes 
happens in man, thereby recalling the form usual to the primates and 
some other lower animals. 

The pidp canal is of the same general form as the root, often presenting 
the spindle-shape on section. It is somewhat difficult to enter on account 
of its flattened shape and narrowed channel. 

The canine being larger, stronger, and more robust than the incisors, 
presents fewer elements of mechanical weakness of the crown 
than those teeth. The body of the crown is thicker from the cervix 
3 




The lower canine. 



34 HUMAN ODONTOGRAPHY 

to the morsal point, and is well supported labially by the rounded emi- 
nence of this face and lingually by the columns on that face. The 
median third of the crown is strong enough for self-support, even when 
the mesial and distal columns are destroyed, which is not the case with the 
incisor blade. The morsal point is still strong enough for serviceable 
employment in food reduction. This mechanical structure of the canine 
permits of more extensive operations upon the mesial and distal faces 
of the crown than is possible with the incisors, This obtains even with 
pressure gold fillings, and is, of course, much more applicable to inlay 
fillings. But the important fact must also be taken into consideration 
that the canine having been transplanted from the premolar series, 
in the process of evolution, is subjected to much more stress in the per- 
formance of its duties in food reduction than the incisors. In fact, most 
of the errors of operating upon this tooth are due to the fact that it is 
treated as an incisor rather than a premolar in its artificial restoration. 
The solidity of its support, the deep implantation, the strength of crown, 
all tend to encourage the instinctive hard usage which this tooth receives, 
an instinct which is partly inherited from the stage of evolution of the 
species when it was a useful and effective weapon. On account of this 
hard usage, operations upon this tooth must be planned for the endur- 
ance of great stress, in order that fewer failures shall result from mis- 
apprehension of its office. 



THE TUBERCULATE TEETH 

The very lowest forms in which grinding organs appear are the cusped 
prominences upon the stomacholiths, the gastric mill of the Crustacea. 
The larval stage of some insects also have calcareous grinding organs 
in the stomach or proventriculum. In the lower vertebrates the crushing 
teeth appear first in the fishes which have well-developed pavement 
teeth for crushing shellfish. True tuberculate teeth do no appear, how- 
ever, until the stage of the higher reptiles, some lizards having posterior 
tubercular teeth, which are the forerunners of the molar teeth of the 
mammalia. In the lower mammals the crushing and grinding teeth 
are very simple, as in the bruta, in which the crushing teeth are simple 
dentin cylinders, worn in facets. Gradual progress takes place in the 
evolution of the grinding teeth until the highly developed molars of the 
herbivora are attained, on the one hand, and the cutting premolars of 
the carnivora, on the other — both highly developed for reducing special 
kinds of food. Between these two extremes are many intermediate 
forms, variously adapted to omnivorous diets. Among these inter- 
mediate forms man is found, whose simple, tuberculate denture is adapted 
to an omnivorous diet. The grinding teeth of man are of primitive 
bunodont type, which recalls early geological forms of molars, harking 



THE TUBERCULATE TEETH 



35 



back to his ancestral prototype of the tertiary formations. The evolu- 
tion of the human molars is a beautiful study — as has been previously 
illustrated. 

The Bicuspids. — The bicuspids in man are homologous with the pre- 
molars of the quadrumana and other lower mammals. They succeed 
and displace the molars or grinders of the deciduous set. They are 
placed next after the cuspids in both jaws, and midway between the 
cutting and grinding teeth. Their function is the crushing of food 
preparatory to mastication. 

The Upper Bicuspids. — The upper bicuspid is formed by duplication 
of the primitive cone and cusp in a transverse direction (Fig. 17, a). 
Viewed from the standpoint of comparative dental anatomy, the external 
cone is the canine cone — and to this is added the internal or bicuspid cone, 
the tooth being a double canine. The bicuspids are the first of the com- 
plex teeth. The internal cusp is formed by the raising of the inner prim- 
itive cusp of the cuspid and the development of a root to support it. The 
distinctive feature of the architecture, therefore, is its formation from 
two cones. 

The upper first bicuspid approximates the cuspid on the distal 
side. 



Fig. 17 




b c 

The upper bicuspids. 




The upper bicuspids. 



The buccal face (c) is of spear-head shape, similar to that of the cuspid. 
This is more apparent in some lower mammals than in man, in whom it 
is much reduced and rounded, so as to give usually the appearance of a 
long, rounded oval. The buccal cusp (c) rises sharply and prominently 
from the lower centre of the face, from which a strong ridge (d) leads up 
to the cervical border. The mesial and distal lobes (e, e) are rarely 
conspicuous, and the furrows between them and the central ridge lead 
but half-way up the crown. The lobes sometimes have prominent 
points at the morsal margins, which in lower mammals become pro- 
nounced cingulums. The buccal marginal ridges descend from the 
points of the cusp to the points of the lateral lobes. The distal ridge 
is usually longer than the mesial. The cervical border is rounded and 
oval from side to side. 

The lingual face (J) is full and rounded, more or less straight perpen- 



30 HUMAN ODONTOGRAPHY 

diculariy, and rounded mesio-distally. It is convex in both directions. 
The lingual cusp rises over it full, but is blunt and round; the marginal 
ridges are rounded, not angular, and curve sharply around to meet the 
mesial and distal marginal ridges. 

The mesial face (Fig. 18, g) is wide and flat transversely, full at the 
morsal surface at the marginal ridge; which is prominent, and descend- 
ing flat to the cervix, where a depression (h) occurs which extends well 
up the face. 

The distal face is of similar form, but is rather more convex and the 
portion at the marginal ridge more prominent. The depression from the 
root does not extend so far up on the face. 

The morsal surface shows an abrupt change from that of the cuspid 
next to it, as it presents two distinct cusps or points instead of one. One 
cusp is on the buccal margin (/) of the crown, and one on the lingual (k), 
and they are named the buccal and lingual cusps. The buccal cusp is 
sharp and prominent, and is not unlike the single canine cusp. The 
lingual cusp is broader and more rounded — indeed, it is preferable to 
term it a tubercle. 

The outline of the morsal surface is imperfectly quadrate and is 
bordered by well-marked marginal ridges, named as follows: 

The mesial marginal ridge (/), bordering the mesial face of the crown; 
the distal marginal ridge on the distal side (m), the buccal marginal 
ridges (n) descending from the point of the buccal cusp to meet the buc- 
cal terminations of the distal and mesial marginal ridges at the angle 
formed by the junction with the buccal lateral lobes (o), and the lingual 
marginal ridges (p), descending from the lingual tubercle to meet the 
lingual termination of the mesial and distal marginal ridges. 

The triangular ridges descend from the cusps toward the centre of 
the tooth and unite at the central groove In defective teeth they do 
not fuse, leaving a fault or fissure which usually becomes the seat of caries. 
This groove or sulcus extends from one lateral marginal ridge to the 
other mesio-distally (r), and widens into the mesial and distal sulci at 
each end. The triangular grooves (s) run from the mesial and distal 
sulci toward the mesial and distal angles, dividing the marginal ridges 
from the triangular. They also frequently become the seat of caries in 
imperfectly formed teeth. 

The neck of the first bicuspid is compressed or spindle-shaped (t), 
the enamel line rising on the buccal and lingual sides and dipping down 
on the mesial and distal. The enamel margin tapers off gradually on 
to the root. A wide, deep depression usually occurs (u) on the mesial 
side of the neck, leading to the groove on the root. On the distal face 
this is not so well marked. 

The root is much flattened mesio-distally, with a decided groove ex- 
tending up both sides. This grooving tends to cause bifurcation of the 
root, which actually occurs in one-third of the cases, especially in persons 



THE TUBERCULATE TEETH 37 

of strong build. This bifurcation is a persistent relic of lower forms 
of the premolars, as in the apes. 

The root canal is flat at the neck, and nearly always bifurcated, even 
when the root is not separated. This is readily seen by holding a bicus- 
pid having one root, up to the light, when the central portion w^ill be 
observed to be translucent. The usual bifurcation necessitates the search 
for both canals in every case in treating this tooth. 

The upper second bicuspid (w) approximates the first on the distal 
side, and is similar to it in every way, except that it is usually smaller and 
more rounded in all directions. The sharp features, conspicuous ridges, 
etc., are not so strongly marked. The cusps are reduced, the ridges more 
rounded, and the morsal face more flattened, and it is often wrinkled. 
The triangular ridges are more likely to be united, thus making the 
crown stronger. The crown is thinner mesio-distally. The neck is 
more rounded or oval. 

A most conspicuous difference is in the root, which is narrower labio- 
lingually, is more rounded, and is rarely bifurcated. It is sometimes 
cylindrical or cubical in form. It is disposed to be turned, and is often 
crooked. The pulp canal is single and readily entered. 




The lower first bicuspid. 

The Lower Bicuspids. — These are placed next after the lower canines 
on the distal side. In form they are not truly bicuspid, for the first is 
unicuspid and the second is tricuspid in the pure typal forms; but they 
are arbitrarily termed bicuspids on account of their position as com- 
pared with the upper bicuspids, which are typically bicuspid. 

The architectural form of these teeth is that of the single cone, the 
crown being augmented in various directions by the addition of cm- 
gules to the primitive cusp. 

The lower first bicuspid is a well-formed transitional tooth, for it 
grades from canine to bicuspid and is typically composite. It more 
closely resembles a canine than a bicuspid in its usual form, because 
the inner cusp is almost suppressed and is rarely as large as the outer 
one (Fig. 19, a). In fact, it looks like a canine with a cingule. raised 
upon its inner face. This cusp is really a cingule, for it is rarely raised 
to the full height of a cusp. 



38 HUMAN ODONTOGRAPHY 

It varies much in size from a mere point on the basal ridge (b) on 
through various degrees of development, up to a full cusp as large as 
the buccal cusp, when the tooth becomes a true bicuspid. The tooth is 
therefore essentially a primitive unicuspid premolar, of the form of this 
tooth in some of the lower primates. 

The buccal face (c) is caniniform, or a long oval in outline, with 
the cusp rising as an abrupt point above it. The angle of the junction 
of the marginal ridges may stand out prominently. The face curves 
markedly toward the lingual side, so that the buccal cusp becomes 
central to the long axis of the tooth (a). The cervical border is rounded 
at its margin and convex from side to side. The lobes are not marked. 

The lingual face (d) is convex from side to side and straight vertically, 
but is not perpendicular, as it is directed toward the lingual side. Its 
height depends upon the height of the lingual cingule, which varies from 
a mere buccal ridge through various degrees up to the full-sized cusp. 

The mesial and distal surfaces are of similar form, convex from side 
to side (a, b), slightly flattened at the cervical border and flaring out to 
meet the full marginal ridges, which are round and prominent. The 
prominence of these ridges and the inward inclination of the lingual 
face gives the crown a decided bell shape, tapering to the neck (d). 

The morsal surface (e) is peculiar and differs from every other tooth 
in its great variability and the extremes which it may present, from 
being that of a full bicuspid to a mere canine. This face is nearly circular 
in outline, the widening of the lateral surfaces by the spreading of the 
marginal ridges (/, /) adding to the width. The buccal cusp (g) is large 
and prominent, and is also drawn toward the centre of the tooth to 
accommodate the occlusion. Sometimes it is high and sharp when the 
lingual cusp is reduced, and is low and blunt when the latter is en- 
larged — appearing to have an inverse ratio in size to the inner cusp. 
The lingual tubercle or cingule varies much in size, from a mere point 
on the basal ridge, above the cervical border, to a pronounced cingule, 
a larger cingule, a small cusp, then a full cusp, the basal ridge (h) being 
raised with it. The ridges are the mesial and distal marginal ridges 
(i, i), which are bowed out round and full and are always pronounced; 
the buccal marginal ridges (/, /), leading down from the buccal cusp to 
form an angle with the mesial and distal marginal ridges; the basal 
ridge, when the lingual cingule is lowered (b); and the triangular ridge 
of the buccal cusp, which is always large, and when the inner tubercle is 
reduced leads down as a high central eminence. The lingual cingule, 
as a rule, possesses no triangular ridge. 

The central groove usually crosses the central ridge (k), but not 
always, being often bowed around its lower termination. Sometimes the 
ridge is crossed by a sulcus. The groove terminates in a sulcus at each 
end, with slight triangular grooves branching up on the buccal cusp. 

The neck is usually oval on section, being much constricted, the crown 



THE TUBERCULATE TEETH 39 

flaring upward from the cervical portion, giving the crown the well- 
known bell shape. The enamel line dips but slightly, being usually 
level on all four sides. The buccal border sometimes presents a promi- 
nent ridge. 

The root is single, long, tapering, and may be nearly round, but is 
usually flattened mesio-distally. It is sometimes thick the greater part 
of its length, and terminates in an abrupt, round, blunt apex (c, d). It 
is very liable to be crooked. It is rarely bifurcated and does not pre- 
sent grooves on its lateral faces. 

The pulp canal is constricted and flattened at the neck, and the back- 
ward inclination of the teeth makes it difficult to enter. The possibility 
of the root being crooked and the peculiarity of its anatomical relation- 
ships 1 also increase the uncertainty of treatment, which makes the 
pulp canals of the lower bicuspids difficult to deal with. 

The lower second bicuspid approximates the first on its distal side. 
It resembles the first as regards the general form of the crown, its taper- 
ing bell shape, the constriction of the neck, and the shape of the root. In 
all these features there is little difference be- 
tween these teeth, and the description of the first 
will apply also to the second bicuspid. 

The morsal surface (Fig. 20), however, differs 
very materially from that of the first. This is 
circular in outline like the first, and the buccal 
cusp is full and rounded (a), but the inner cusp 
is divided by a groove (b) running over it, into 
two parts, so that it is reallv divided into two 

i i rrn • i 1 1' 1 1 • T ^ e morsa l surface of the 

tubercles. I his makes the lower second bicus- lower second bicuspid. 
pid in its typal form a tricuspid tooth, so that 

it differs from the lower first, which has but one cusp, and from the 
others, which have but two cusps. The lingual tubercles vary much in 
size, so that one may be suppressed and the tooth seem a bicuspid. 
The mesial lingual tubercle (c) may be of large size and be devel- 
oped at the expense of the distal (d); this may be a mere cingule on 
the distal marginal ridge and appear on the distal side, but it is always 
present. 

The morsal groove is (e) triangular in design, passing between each 
of the three tubercles. A well-marked triangular ridge descends from 
each of the cusps. 

The tricuspid form of the morsal surface of this tooth is, of course, 
a reproduction of the trituberculate premolars of the lower primates, 
and of still lower mammals, although the triangular form of the crown 
is lost in man. 

The Molars. — The molars in man are twelve in number, three on each 
side of each jaw, and are placed at the rear of the arch, opposite the strong 

1 See Chapter on Extraction of Teeth. 




40 



// V M AN ODONTOGRA PH Y 



triturating muscles, for the purpose of crushing and masticating food. 
They are important factors in alimentation and contribute to the func-. 
tion of digestion by preparing food for the stomach. Their loss impairs 
this function seriously and leads to derangement of the stomach by over- 
taxing it with imperfectly masticated food substances. 

The Upper Molar. — The typical upper molar is formed by the fusion 
of three cones, as is plainly observed in the three roots and the three 
tubercles (Fig. 21, .4). The tricuspid molar, therefore, is a primitive 
form, and is rarely seen in man, the normal form being quadrituber- 
culate. The fourth additional cusp, the disto-lingual (6), is merely 
a supplemental cusp added to the crown. An upper molar is, therefore, 
composed of three tubercles, and a cingule which has not yet developed 



Fig. 21 




rh 



-rj 



d f 



9 h i 



Architectural diagram. 






The upper molar. 



a root to support it. The trituberculate molar is the primitive form of 
this tooth, the quadrituberculate appearing later, and is found in only 
a few living forms, as some of the lemurs and the insectivorous and 
carnivorous mammalia. In man there is sometimes a reversion of the 
upper molar to the trituberculate form, which is a marked degeneracy 
in the form of this tooth. In an analysis of this tooth, therefore, the 
mesio-buccal tubercle (c) is the canine cusp; the mesio-lingual, the biscus- 
pid cusp (d); the disto-buccal, the molar cusp (e), and the disto-lingual 
is but a supplemental cusp — it is not a true cusp, as it has no root to 
support it. 

The architecture of the upper molar presents some interesting feature's. 
We observe that the crown is in a general way a geometrical form, a 
cube (/), when perfect and symmetrical. It is suggestive of symmetry, 



THE TUBERCULATE TEETH 41 

but when taken with the root form is not quite perfect, for it is sup- 
ported on three roots instead of four to correspond with the four tuber- 
cles at the four corners. So it lacks the ''harmony of adequate support/' 
which is a cardinal principle in architecture. But the crown separ- 
ately is a symmetrical form, a cube, although the angles are rounded 
off and the corners and points are toned down and not acute. We notice 
that there are four strong columns, one at each of the four corners (g). 
They are connected on the four sides by the marginal ridges acting as 
strong connecting arches (Ji). These arches are related to the columns 
of the crown, and both are impressively proportioned. The cusps may 
be likened to the capitals of the columns, and the descending marginal 
and triangular ridges to the cornice, gathered together to form the cap- 
itals. The triangular ridges may be considered girders (i), binding 
the four together and also bracing the square obliquely. Or, the four 
triangular ridges running to the centre may be regarded as half-arches 
or buttresses, supporting the roof vault, — the grinding face. Other 
elements could be marked out in an architectural study of the crown 
of this tooth, showing its beautiful design and symmetry. 

The upper first molar approximates the second bicuspid on its distal 
side. There is a marked and abrupt change in form, as the molar has 
double the number of cusps of the bicuspid — being formed like two 
bicuspids fused together. The four tubercles constitute an extension of 
surface and a further adaptation to functional requirements. The 
crown is large and cubical in form, and more or less rounded. 

The buccal face (K) is wide and rounded. It is twice the width of 
the bicuspids. It is broadest at the morsal margin, narrowing upward 
to the cervix, where it is widely rounded or arched. A vertical depression, 
the buccal groove (/), extends from the cervical border to the morsal 
margin, dividing the face into two oblong rounded eminences, the mesial 
and distal buccal lobes (m m). 

The lingual face (N) is more rounded than the buccal, the cervical 
portion being the most convex (o), the mesial and distal sides being 
depressed toward the single lingual root. The morsal half is divided by 
the lingual groove (</), vvhich descends over the lingual marginal ridge 
between two lobes, the mesial (r) and distal (p), which are usually much 
rounded. The morsal half of the face curves toward the grinding sur- 
face. The mesial lobe sometimes presents the lingual cingule (s), a 
sort of fifth tubercle of greater or less size. A groove branches from 
the lingual groove and extends over, between the cingule and crown. 

The mesial face (T) is flat longitudinally, descending from the mar- 
ginal ridge to the cervix in a nearly straight line. Bucco-lingually it is 
convex, nearly flat at the marginal ridge, and rounded at the cervix, 
being depressed toward the lingual root. Sometimes a depression from 
the bifurcation of the mesio-buccal and lingual roots extends part way 
up on the face (u). 



42 HUMAN ODONTOGRAPHY 

The distal face is similar to the mesial except that it dips more toward 
the cervix, and is, perhaps, more rounded toward the lingual root. 

The morsal surface (Fig. 22) is the most important part of this tooth, 
and shows features that make it interesting and unique. The abrupt 
change from the bicuspid form is notable, for there are presented four 
cusps, a doubling of the number; the outline of this face presents a 
square form with tubercles at each corner, the mesio-buccal (a), the 
disto-buccal (b), the mesio-lingual (c), and the disto-lingual (d); the 
latter is erratic and may be either pronounced or quite reduced in size. 

There are four marginal ridges: the mesial (e), buccal (/), distal (#), 
lingual (h), the oblique (f), and the four triangular ridges (J). The 
oblique ridge connects the mesio-lingual with the disto-buccal tubercle 
and is really the remnant of the marginal ridge of the tricuspid molar; 
the fourth cusp, the disto-lingual, being raised up on the disto-lingual 
side. The four triangular ridges descend from the four tubercles toward 
the centre of the tooth, the oblique ridge being formed by the fusion of the 
triangular ridges of the mesio-lingual and disto-buccal cusps. 

Fig. 22 






3 c 

The morsal surface of the upper first molar. 

There are two fossse (&), one mesial and the other distal to the oblique 
ridge. Sometimes the latter is cut by a groove or sulcus (I) which ex- 
tends from the mesial to the distal fossa. Sometimes by the reduction 
of the disto-lingual lobe and cusp, the mesial fossa is extended and 
becomes central to the crown. A groove extends from the mesial fossa 
over the buccal marginal ridge (m) quite on to the buccal face, dividing 
the mesial from the distal buccal lobes. A groove also extends over the 
lingual marginal ridge (n) down upon the lingual face, dividing the 
lingual lobes. When this groove becomes a fissure and caries ensues 
the disto-lingual cingule readily breaks away, this cingule being a weak 
feature in the mechanical design of this tooth; cutting the distal mar- 
ginal ridge also weakens this cusp. The triangular grooves branch from 
the two fossse on to the cusps, dividing the triangular from the marginal 
ridges. 

The neck of this tooth is of rounded rhomboid form on section (o), 
widest at the buccal side. The enamel is almost level on all four sides, 
dipping downward slightly on the mesial and distal. A depression 
occurs at the bifurcation of the buccal roots, and an inward inclination 
on the mesial and distal sides. 



. m^, — -. _ — » 



THE TUBERCULATE TEETH 43 

The roots are three in number (Fig. 21), two on the buccal side, which 
are small and flat or round, and one on the lingual side, which is large 
and rounded. The roots are usually separated, but may be found 
united, by a septum of cementum, in various directions. The mesio- 
buccal root is the larger of the two buccal roots, and forms a second 
turning-point or spring of the arch. All the roots are slightly bent 
and may be very crooked. 

The pulp chamber branches into three canals, one in each root. The 
lingual canal is large and open and is readily entered. The canals of the 
two buccal roots are small and fine, and, with the possibility of crooked- 
ness in the roots, present the most difficult problems as to treating and 
filling found in the whole denture. 

The upper second molar is similar to the first in some respects, but 
very different in others. It is rather smaller, is not usually full and 
square, but disposed to become rhom- 
boid in form (Fig. 23, a, b), by disto- Fig. 23 
mesial compression. 

The buccal face is similar to that of 
the first molar, and the same descrip- 
tion will apply to it. If any difference is 
found it is that the face is strongly com- 
pressed from front to back, and the 
disto-lingual cusp is more reduced as a 
constant feature. b c x d 

The lingual face (c) is different from The upper second molar. 

that of the first molar in that by the 

suppression of the disto-lingual tubercle (r/) and the distal lobe the 
mesio-lingual lobe is enlarged so that it occupies the entire face, which is 
full, rounded, and convex (e). It is rarely divided into two lobes, as in 
the first molar, owing to the enlargement of the mesial lobe and the push- 
ing backward of the oblique ridge, which throws the lingual groove on 
to the distal lingual angle (d) ; or the groove may be absent altogether. 

The mesial and distal faces are similar in form to those of the first 
molar, being perhaps more flattened. 

The morsal face is similar to that of the first molar, except that the 
tubercles are less pronounced and the distal ones are reduced in height 
to accommodate the upward curve of the line of occlusion at this point. 
The disto-lingual cingule is smaller than that upon the first molar, and 
is often barely marked. This throws the oblique ridge more to the distal 
side and enlarges the mesial fossa. The various grooves are the same as 
on the first molar, except that one, the lingual, may be lost. 

The neck is less regular in outline than that of the first molar, as the 
crown varies so much in shape. It is more flattened mesio-distally and 
depressed toward the roots. 

The roots are the same in number and general form as in the first 




44 



HUMAN ODONTOGRAPHY 



molar, but spread less and are more irregular in form. They may con- 
verge or be crooked, or may be fused together. This makes the pulp 
canals more difficult to treat. Sometimes the three roots are completely 
fused, as in the third molar, and the canals may coalesce; or the canals 
of the two buccal roots may run into one. The irregularity and uncer- 
tainty of the form of the roots make this tooth difficult to deal with in 
treating its pulp canals. 

The Lower Molars. — The lower first molar approximates the lower 
second bicuspid on its distal side. It is the first of the true grinders 
of the lower jaw and the largest tooth in the dental series. Unlike the 
upper molars the transverse diameter is less than the mesio-distal. The 
greater width is found across the base of the disto-buccal tubercle. 
The crown is square or trapezoidal in form, depending on the size of the 
fifth tubercle. Being quinquetuberculate, the crown is broadened by the 
multicuspid grinding face. The buccal face is inclined toward the centre 
of the tooth, for its morsal half, to accommodate the occluding teeth. 



Fig. 24 




Architectural diagram. 

9 f 




B 

The lower first molar. 




Architecturally, the tooth is formed of four cones (Fig. 24, A), and 
may be roughly divided into four quarters. There are four primitive 
cones with their tubercles and one cingule in the structure. 

The morsal surface (B) is trapezoidal in outline, the buccal line being 
the longest. The buccal angles are acute, while the lingual are rounded 
and obtuse. 

There are five tubercles, two on the lingual margin and three on the 
buccal. They are named the mesio-buccal (c), median buccal (d), disto- 
buccal (e), disto-lingual (/), and mesio-lingual (g). These tubercles are 
less obtuse and more rounded than those of the other grinding teeth, the 
mesio-buccal usually being the largest; the others are not so prominent, 
rarely raised and sharp. 



THE TUBERCULATE TEETH 45 

The ridges are: the marginal ridges — buccal, distal, lingual, and 
mesial — and the five triangular ridges descending from the five tubercles 
toward the centre of the tooth. 

The grooves and sulci upon the morsal surface are very irregular. A 
deep sulcus traverses the face from the mesial to the distal marginal 
ridge. A groove runs off toward the lingual side, dividing the lingual 
cusps (i), sometimes cutting the lingual marginal ridge, but rarely 
reaching over on the lingual face. A groove runs toward the buccal 
side, dividing the rnesio-buccal from the median tubercle (j), cutting 
the marginal ridge and extending over quite on to the buccal face. This 
groove often becomes the seat of caries, owing to the enamel structure 
being faulty. Another groove extends toward the disto-buccal angle (ifc), 
dividing the median from the disto-buccal tubercle, and rarely extends 
over on to the buccal face. A groove may extend distally, cutting the 
distal marginal ridge (/), and one mesially, cutting the mesial marginal 
ridge (m), but these are not usually marked. The triangular groove 
running up on each side of the triangular ridges (/?) divides these from 
the marginal ridges. Supplemental grooves may divide the triangular 
ridges again. The pits at either end of the sulcus may become the seat 
of caries through faulty formation. 

The buccal face (C) is an irregular trapezoid in form, the morsal mar- 
gin being longest; the mesial and distal sides converge toward the cer- 
vical border, which is rounded. The morsal margin is broken by the 
three tubercles rising upon it. The buccal face is convex in all direc- 
tions, that from the morsal to the cervical borders being the most marked, 
owing to the morsal half converging toward the centre of the tooth. 
The buccal groove (o) leading over from the morsal face divides the 
face into two lobes, which are full and rounded. Sometimes the disto- 
buccal groove cuts off another lobe, thus making three lobes on the buccal 
face. These grooves sometimes lead to the cervical border, but usually 
terminate in the middle of the face in a pit, which may become the seat 
of caries through faulty formation of the enamel. 

The lingual face (D) is wide, rounded, smooth, and convex, rather 
straight perpendicularly, leaning in the lingual direction. It forms a 
sharp angle with the morsal surface, which is surmounted with two 
tubercles. Sometimes, but rarely, the lingual groove passes over on to 
this face. 

The mesial and distal faces (s) are wide and flattened transversely, 
but convex vertically. They are trapezoidal in outline, the morsal 
border being longer. The cervical border is more convex, and dips 
toward the neck of the tooth. 

The neck (/) is very regular in outline and contour. It is approxi- 
mately square with all four sides depressed in the centres. The mesial 
and distal are depressed at the origins of the grooves leading down 
upon the roots; the lingual and buccal are depressed at the bifurcation 



46 HUMAN ODONTOGRAPHY 

of the roots, the depression, which is wide and deep, extending up on 
to the neck, especially upon the buccal side. The enamel line is quite 
irregular, dipping down on the lingual and buccal, and leading well 
up on the mesial and distal sides. 

The roots are two in number, placed with their longer diameter trans- 
versely to the jaw. They are wide bucco-lingually, and flat and narrow 
disto-mesially, being situated distally and mesially to the crown. The 
posterior is formed of the two posterior cones, and the anterior of the 
two anterior cones (.4). This is plainly shown in the formation of the 
roots, which are grooved both distally and mesially, and in the tendency 
to bifurcation, which sometimes actually occurs. They divide close to 
the crown, so that the grooves of bifurcation extend well up on the neck. 
The distal root is thicker and more rounded than the mesial, the latter 
being more flattened, with the grooves deeper, and it is more often 
bifurcated. Both are deflected from the median line. 

The pulp canal is shaped like the roots, with two main branches. 
The distal branch is the larger, being round and open, as the root is more 
rounded. The mesial branch is flat and spindle-shaped, being difficult 

to enter, and usually having 
FlG - 25 two sub-branches, follow- 

f 9 ing the buccal and lingual 

divisions of the root. 
These sub-branches are 
small and hair-like and 
troublesome to enter. 
The lower second molar 

The lower second molar. (Fig- 25) differs from the 

first in many respects. It 
is of the same general form, but is more quadrangular, as it has but 
four tubercles. It is more rounded and symmetrical than the first, the 
four cones and four primitive tubercles being well marked. The ab- 
sence of the fifth tubercle leads to most of the differences between the 
second and the first molar. 

The morsal face (c) has but four tubercles, one at each corner of the 
face, differing from that of the first molar, which has five. The fifth 
tubercle rarely appears in the higher races of mankind, but is some- 
times found in the low savage races, and occurs regularly in the apes. 
It is not uncommon in the negro, but is absent, as a rule, in the European 
races. The tubercles are symmetrical, rounded and obtuse, the lingual 
being, however, sharper than the buccal. 

The sulci describe a cruciform shape, separating the four tubercles 
symmetrically from each other. The buccal groove sometimes continues 
on to the buccal face, rarely to the lingual. The triangular grooves 
run up on the morsal triangular ridges. The marginal ridges are well 
marked, the mesial and distal being often divided by grooves. The 



««§# 





THE TUBERCULATE TEETH 47 

triangular ridges are usually well marked, leading to the centre of the 
tooth. They are full and strong. 

The buccal face (d) is convex and of more regular form than that 
of the first molar. It is divided into lobes (e, e) by the buccal groove 
(d), which is rarely deep. A pit is often found in the centre of the face, 
which may become the seat of caries. The face is curved toward the 
centre of the tooth, as in the first molar. 

The lingual face is similar to that of the first molar, but may be more 
rounded toward the morsal border. It is symmetrically convex in both 
directions. 

The mesial and distal faces (J) are similar to those of the first molar, 
except that, the crown being smaller, they may be more perpendicular, 
but are well rounded. 

The neck (g) is more regularly formed than that of the first molar, 
the margin of the enamel line being quite as irregular. It may be more 
constricted. 

The roots (h, h) are similar to those of the first molar, but are more 
rounded in shape, are usually crooked, and on that account difficult to 
treat. 

The pulp canals are similar to those of the first molar, but the tend- 
ency to crookedness renders treatment quite difficult. The direction 
of irregularity of form is so uncertain that no rule can be applied to it. 

The Third Molars. — The upper and lower third molars can best be 
described together, on account of their similar eccentricities. They 
are very irregular as to the time and to the frequency of their appearance 
in civilized man. About one-half of the individuals of European races 
erupt them at the normal period, i. e., seventeen to twenty-one years of 
age. In one-fourth they erupt at irregular intervals to the thirtieth 
year, and in the remainder they may appear later, or the first, second, 
third, or all of them, may be absent altogether. In one series of forty 
adult skulls observed, twelve had one or more absent. The absence and 
other erratic peculiarities of these teeth sometimes seem to be hereditary, 
and can be traced in families through several generations. 

The tooth is often reduced in size and may be a mere peg (Fig. 26, a). 
It is of very irregular form in civilized races, but is as large and as well 
formed as the other molars in most races low in the ethnological scale. 
The contraction of the jaws through disuse has much to do with the mal- 
development of this tooth, and it is often so cramped for room as to pro- 
duce distressing irritation which necessitates its removal. Impaction 
and malposition of the third molars render them difficult of extraction 
and are the fruitful source of many serious lesions. (See the chapter on 
Extraction of Teeth.) 

The upper third molar is more or less similar to the other upper molars 
when perfect and well developed, but it is very erratic as to form and 
structure, 



48 



HUMAN ODONTOGRAPHY 



This tooth, when well formed, is of trituberculate form (6), the disto- 
lingual cingule being suppressed. This cingule diminishes gradually 
from the first molar, in which it is well formed, to the second, where 
it is reduced, then to the third, where it is almost or entirely absent. 
The oblique ridge becomes the posterior marginal ridge (c), as in 
the typical trituberculate molar. The three tubercles are reduced and 
rounded. The sulci usually degenerate into fissures, as the formation 
of this tooth is notoriously faulty. The enlarged mesial fissures thus 
become the seat of extensive caries. 

The buccal face resembles that of the first and second molars, but is 
more rounded. 

The lingual face (d) is full and rounded, with but a single lobe, owing 
to the reduction or absence of the disto-lingual tubercle. 

The mesial face (e) is similar to that of the second molar, but reduced, 
and the distal face is round and short, as no tooth succeeds it in the rear. 

The neck is constricted and tapers toward the conate roots. It is of 
a rather rounded triangular shape. 



Fig. 26 





The upper third molar 



The lower third molar. 



The three roots of the upper molars are, in the third, usually more 
blunt, conate, short in form, and may curve backward. In lower races 
and sometimes in individuals having strong osseous organizations, the 
typical three molar roots are found. Sometimes there are multiple 
roots, which are likely to be curved in various directions, and may have 
decided hooks. 

In the large conate root the pulp canals usually coalesce, but in cases 
in which the root is divided there will also be division of the pulp chamber. 

The lower third molar is similar to the other lower molars in general 
form (Fig. 27, a), but is probably not so erratic and not subject to such 
extreme variations. The crown is quadrangular in section, the angles 
rounded. 

On the morsal face (b) there are four principal tubercles, as in the 
second molar, but this may be supplemented by the extension of the 
disto-marginal ridge into a cingule or heel (c). This heel is rather 
erratic; it may be large or small, thus modifying the size of the morsal 
surface. Sometimes the face is wrinkled and, like this tooth in the 
orang-outang, the sulci exhibit the cruciform shape similar to that of the 



THE TUBERCULATE TEETH 49 

second molar. The many grooves leading away from the main sulcus 
may be imperfect and become the seat of caries. The buccal groove 
running from the morsal on to the buccal face (a) is very subject to imper- 
fection. 

The four lateral faces are similar to those of the second molar, except 
that the distal is more convex and full, and often very prominent if the 
fifth cingule is well developed. 

The neck is of similar shape to that of the second molar. 

The roots are similar to those of the other lower molars, but generally 
smaller as compared with the crown (d). They are usually divided like 
the others, but the two may be fused together, or be closely opposed. 
In either case they are usually projected distally more or less, leading 
backward into and under the ramus, thereby rendering extraction of 
this tooth difficult and dangerous, especially where the maxilla is of 
dense structure or where there is impaction. The roots are usually 
more rounded, especially the distal one, than those of the other molars. 

The pulp canals are generally divided, whether the root is or not. 
As the roots are usually crooked, the difficulty of entering them is in- 
creased as the canals follow the form of the roots. 

Fig. 28 





The fourth molar. 

Fourth molars sometimes appear as supernumerary teeth, and are 
either fused to the upper third molar in a variety of uncouth forms 
(Fig. 28, a) or erupt separately as mere peg-shaped teeth between the 
buccal faces of the second and third molars (b) or at the distal aspect 
of the 'atter tooth. The fourth molar rarely appears as a full molar, 
except in some of the large-toothed races, as negroes, Australians, etc., 
and then usually in the lower jaw. Among the negroes in Africa the 
fourth molar is sometimes found in full form as a typical molar. 

The tuberculate teeth, the bicuspids and molars, present many points 
of mechanical structure, with reference to operations upon them, that 
are of interest and importance. Beginning with the upper bicuspid, we 
find that being composed of two cones cemented together longitudinally, 
it is essentially a weak tooth. The triangular ridges being imper- 
fectly fused at the transverse sulcus (indeed, this point is often the seat 
of a congenital fissure), the cusps are unsupported. The main 
dependence of the two cones for union and binding together is the power 
4 



50 HUMAN ODONTOGRAPHY 

of the marginal ridges, and when these are destroyed the crown readily 
splits, the buccal or lingual cusp breaking away with the wedging and 
force of mastication. When from extensive caries the approximal 
faces are destroyed and an elaborate compound filling is necessary, the 
lingual cusp, the one that most frequently splits off, should be reduced 
by grinding, so as to lessen the danger from wedging food. While pres- 
sure fillings are, of course, dangerous, there is also danger from inlays 
by reason of the too extensive cutting out of the sulcus and consequent 
weakening of the cusps. There should be as little transverse cutting as 
possible in order to guard this weak point in these teeth. 

In the lower bicuspids the same conditions do not obtain, as their 
architecture and mechanical structure are entirely different. In the 
lower first bicuspid the transverse ridge is strong and well fused, so that 
the splitting off of either cusp is very rare. The second bicuspid is also 
of stronger mechanical structure. The weak point in both these teeth 

is the marginal ridge, which, by reason 
Fig. 29 of the bell-shaped, tapering crown is not 

well supported, and if undermined, readily 
chips off. Therefore, approximal fillings 
on these teeth should be well anchored 
on the morsal surface and undercuts 
avoided. Attention must also be given to 
the lingual occlusion of these teeth, 
which increases the stress upon all 
operations upon them. 

The upper molars are of beautiful and 
wonderful architecture, as before de- 
scribed, and present an interesting study. 
Negro top jaw with fourth molar. The greatest point of weakness in these 

teeth is the disto-lingual cusp, the hypo- 
cone, which often breaks away when undermined by distal caries, as the 
fusion with the oblique ridge and the protocone is weak. This should be 
obviated, after filling, by grinding down the point of the cusp. It is danger- 
ous to cut the oblique ridge, for when the marginal ridges are destroyed 
it becomes the main binding girder of the crown. When this is under- 
mined by caries the crown becomes so weakened that it readily splits. 
The introduction of the inlay, however, has greatly lessened the mechan- 
ical dangers of operating upon these teeth that cannot be avoided with 
the pressure fillings. Mesial inlays should, of course, be carried into the 
mesial sulcus and the buccal border preserved as much as possible 
for the esthetic effect. Indeed, extensive caries on this tooth can 
be better treated with the inlay than with the shell crown, and the 
natural crown be better preserved. 

The lower molar is different from the upper in its mechanical design, 
and the lingual occlusion presents different problems. In the evolution 




THE TUBERCULATE TEETH 51 

of its crown it will be remembered that the protoconid shifts to the 
buccal side and becomes the mesio-buccal cusp. The triangle of the 
lower molar is just the opposite, therefore, of the upper and carries two 
cusps, the two mesial, the third having been lost in the process of evo- 
lution. The talonid, therefore, supports three cusps, the two distal 
buccal and the disto-lingual, which are, therefore, weaker than those of 
the trigonid. Hence we have more breakdowns of the distal half of the 
lower molars than of the mesial. This must be considered in operating 
on this tooth, not making deep undercuts to weaken the cones, but 
depending upon occlusal retention. The cutting of the transverse ridges 
does not weaken the crown except when the cones are separated too 
deeply, which results in the splitting off of the lingual half of the crown, 
which is not uncommon. So the grinding of the lingual cusps must again 
be resorted to to prevent the danger of the wedging of food. The crown 
of the lower molar is essentially weak and the conservation of its weakest 
points, the junction of the cones, must be considered at all times. A 
knowledge of this weakness is obtained by a study of the evolution of 
the crowns of the molars. 

The mechanical resistance of the molars, as well as their effective- 
ness in the mastication of food, depends much upon the accuracy of 
their occlusion. It is needless to say that this very rarely obtains in 
ordinary dentures. Malposition, extractions, abrasion, dental mutila- 
tions, imperfect and indolent use in the performance of the function of 
mastication, all contribute to the malocclusion of the molars which is so 
prevalent. Imperfect occlusion is productive of abnormal stress upon 
various parts of the crown and its consequent frequent breaking down 
along the lines of the junction of the cones. It follows, of course, that 
the proper procedure is to restore the normal occlusion as completely 
as possible by artificial means. 

The Deciduous Teeth. — The deciduous teeth are those which appear 
in infancy and serve the purpose of dental organs during the first years 
of the development of the individual, until the jaws and their environ- 
ment are ready for the larger, permanent teeth to come into place. 
They bear a direct relationship to the conditions of the digestive appar- 
atus and the food required at that early stage. The food of infancy being 
simple and requiring little mastication, the deciduous set are small and 
insufficient for the reduction of more resisting substances. As these 
foods come to form part of the dietary, the larger teeth of the permanent 
set appear and perform the duties of higher functional activity. 

The crowns of the deciduous teeth resemble, in a general way, those 
of the permanent teeth which succeed them, except the deciduous molars 
(Fig. 30, a, d), which are very different from the bicuspids of the per- 
manent set which displace them. 

The incisors of both jaws precede the analogous teeth of the same 
series of the permanent set. They are similar in form, but reduced (6), 



52 



HUMAN ODONTOGRAPHY 



and do not have the main features so characteristically marked. They 
are infantile in form and function. The roots of these teeth are resorbed 
at from the fifth to the ninth year, when the permanent incisors come 
into place, beginning with the lower centrals. 

The cuspids (c) of both jaws are still more reduced from the strong, 
full form of their permanent successors, and are but little more spe- 
cialized than the incisors. They are of the same general form as the 
permanent cuspids, but much less developed. 

But in the deciduous molars are found some important features which 
mark distinctive differences. They are of true molar form as com- 
pared with the permanent molars, but they occupy the place of the 
bicuspids. There are no bicuspids in the deciduous set, the molars 
being of full molar pattern (a, d). 

Fig. 30 • 




c d 

The deciduous teeth. 



The deciduous molars of both jaws are of irregular, quadrangular 
form on the morsal surface, diverging rapidly outward to the neck, 
which presents a large buccal ridge standing out at the margin of the 
enamel, and is rounded off suddenly to the neck, which is much con- 
tracted. This thick ridge is characteristic of the deciduous molars and 
is absent in those of the permanent denture. It is somewhat more 
prominent and bulging on the buccal than on the other faces. In ad- 
justing ferrule crowns to these teeth the gold need not be carried beyond 
this ridge, but burnished over it slightly. 

The morsal surface (e) of the upper deciduous grinders presents the 
characteristic pattern of the upper molars, four tubercles, oblique ridges, 
etc., but reduced and contracted. A distinctive feature is that the mar- 
ginal ridges and angles are more acute and sharp than in the perma- 
nent molars. Sometimes the two lingual cusps are reduced to one and 
the lingual border is rounded and crescentic. 



THE VARIATIONS OF TOOTH FORMS 53 

The second molar is larger than the first and the morsal surface is 
wider. 

The transverse diameter of the crowns of the upper molars is the 
longest. 

The lower molars (d) are similar to the permanent molars in pattern, 
but are more irregular as to the contour of the morsal surface (/). 
The tubercles may be higher than in the upper molars, and the tri- 
angular ridges more marked. The central fossa may be large and wide, 
or divided by the triangular ridges. The second molar is five-lobed, 
unlike the second permanent molar, which has but four cusps. The 
morsal face is decidedly trapezoidal in outline, the mesio-distal diameter 
being greater than the transverse. 

The roots of the deciduous molars are similar to those of the other 
molars, except that they are very divergent to accommodate the crown 
of the advancing bicuspids. They are thin and long, and difficult to 
enter and fill. The pulp chamber is large and open in the crown; as 
a consequence of this caries soon reaches the pulp. Treatment and 
filling of the canals is difficult and uncertain. 



THE VARIATIONS OF TOOTH FORMS 

The teeth may vary quite extensively from the typal forms which 
have been described, and these variations may be due to a number of 
causes. Through all degrees of variation, however, the type is still pre- 
served, unless the tooth form is quite destroyed by pathological causes. 

The general causes of variation may be enumerated as follows' 

1. Incompleteness of development. 

2. Reversion to primitive types. 

3. Temperamental impress. 

4. Pathological lesions. 

1. Lnder incompleteness of development may be grouped all those 
varieties of stunted growth which are the effect of disuse and the con- 
sequent effort of Nature to reduce and suppress the teeth as useless 
parts. The third molar teeth suffer most from these suppressive attempts 
of Nature in the effort toward economy of growth; next to these teeth 
the upper lateral incisors are most frequently affected by reduction of 
size, stunted growth, and suppression. Other teeth are not affected, 
or btit very slightly, by this influence, except in rare cases. 

2. Under the second head, reversion to primitive types, we have a 
variety of interesting phenomena in the form of parts of the human 
teeth which seem to be a zoological legacy. These consist of conspic- 
uous features which reappear and seem to recall forms of the teeth 
observed in some of the lower animal orders, especially the quadrumana 
and insectivora. 



54 HUMAN ODONTOGRAPHY 

Among these features may be mentioned the curved upper central 
incisor with the prominent cingule on the lingual-buceal ridge, making 
a notch which recalls the incisors of the moles; the prominent cingule 
on the lingual face of the lateral incisor, which is not uncommon and 
recalls the form found in the insectivora and some of the quadrumana; 
the extra long, curved canine with extra large median ridges, which 
recalls the large forms of this tooth in the baboons and in the carnivora; 
the double root sometimes found in this tooth is also a reversion to the 
insectivorous type; the v three-rooted bicuspid is a quadrumanous rever- 
sion; the upper tricuspid molar is a primitive typal form, leading back 
to the lemurs and beyond them to the early typal mammals found in 
fossil formations; the notched and grooved incisor recalls the divided 
incisor of the galeopithecus ; the double-rooted lower incisors and canines 
recall insectivorous forms; the unicuspid lower first bicuspid is an insect- 
ivorous type and is often quite marked in man; the fifth cusp on the 
lower second molar is a quadrumanous reversion; the wrinkled surface 
of the lower third molar is like that of the orang, etc. 

There are other features that might be named illustrating the work- 
ings of the law of atavism, by which parts once lost in evolution may 
reappear and be reproduced. 

3. Under the third head, temperamental impress, may be noticed 
those differences of form and structure which have relation to the domi- 
nant temperament in the constitution of the individual. Great differ- 
ences exist between the teeth of different persons, and these are mainly 
dictated by temperament. 

The teeth of the primary basal temperaments present the following 
physical peculiarities, which are characteristic of the particular tempera- 
ment: 

The bilious temperament presents teeth that are of a strong yellow; 
large, long, and angular, often with transverse lines of formation, with- 
out brilliancy, transparency, and of but slight translucency; firm and 
close set, and well locked in articulation. 

The sanguine temperament has teeth that are symmetrical and well 
proportioned, with curved or rounded outlines, and round cUsps; cream 
color, inclined to yellow, rather brilliant and translucent; well set, and 
occlusion firm. 

The nervous temperament has teeth which are rather long, the cutting 
edges and cusps long and fine; color pearl blue or gray, very trans- 
parent at the apex; the occlusion very penetrating. 

The lymphatic temperament presents teeth that are pallid or opaque, 
dull or muddy in coloring; large, broad, ill shaped, cusps low and 
rounded; the occlusion loose and flat. 

Of the binary combinations: 

The sanguineo-bilious has teeth which are large, with strong edges 
and large cusps; color dark yellow, and quality good. 



THE VARIATIONS OF TOOTH FORMS 55 

The nervo-bilious has teeth that are long and narrow, with long cusps ; 
color yellowish or bluish, or both combined; the enamel strong, the 
dentin soft. 

The lympho-bilious has teeth that are large, with thick edges and 
short thick cusps; yellowish in color; enamel of good structure and 
polish, and dentin fair. 

The bilio-sanguineous has teeth of average size, round arch, well- 
developed cusps and edges; rich dark-cream color; excellent in quality. 

The nervo-sanguineous has teeth of average size, good shape, round 
arch, good edges and cusps; rich cream color; enamel and dentin of 
excellent structure. 

The lymplio-sanguineous has teeth of more than average size, shapely 
edges and cusps, rounded arch; color grayish cream; enamel and dentin 
fairly good. 

The bilio^nervous has teeth variable in size and form, sometimes 
broad, again very long with more pointed and long cusps; the color 
generally bluish; enamel fairly good, dentin soft and sensitive. 

The sanguineo-nervous has teeth of average size, good shape, round 
arch ; color grayish blue ; soft and frail. 

The bilio-lymphatic has teeth usually large, with thick edges, short, 
thick cusps, and flat arch; color yellowish; quality good. 

The sangulneo-lymphaiic has teeth of more than the average size, 
broad round arch; color gray; enamel and dentin poor. 

The nervo-lymphatic has teeth of average size, good shape, average 
length, rather round arch; color bluish gray; soft and poor. 

Combinations of the binary temperaments are of the most common 
occurrence in individuals, but there is usually one basal temperament 
that preponderates over the others and gives its characteristic to the 
teeth as a predominating influence. 

4. Under the fourth head, pathological lesions, are to be included 
all those disturbances of nutrition which eventuate in faulty formation 
of the teeth, whether due to specific hereditary diseases, mere malnutri- 
tion, idiosyncrasies, predispositions, defective functional life, etc. But 
this leads beyond the province of this chapter into the field of special 
pathology and embryology. 



CHAPTEE II 

DENTAL HISTOLOGY WITH REFERENCE TO OPERATIVE 

DENTISTRY. 1 

By FREDERICK B. NOYES, B.A., D.D.S. 

The development of our knowledge of the cell has had a most pro- 
found effect upon the entire practice of medicine; in fact, the progress of 
modern medicine dates from the studies of cell biology, the germ theory of 
disease being only one of the phases of this development. In terms of the 
cell theory the functions of the body are but the manifest expression of 
the activities of thousands or millions of more or less independent but 
correlated centres of activity; if these centres or cells perform their 
functions correctly, the functions of the body are normal; but if they 
fail to perform their office, or work abnormally, the functions of the 
body are perverted. In the last analysis, then, all physiology is cell 
physiology; all pathology cell pathology. To modern medicine his- 
tology, or the cell structure of the organs and tissues of the body, 
together with cell physiology, is the rational foundation of all practice. 
This is as true for the dentist as for the physician so far as regards all 
of the soft tissues of the mouth and teeth that he is called upon to treat 
and handle. With caries of the teeth, the disease which most demands 
the attention of the dentist, the case is somewhat different. Caries 
of the teeth is an active destruction, by outside agencies, of formed 
materials which are the result of cell activity (the tissues themselves 
being passive). The cellular activities of organs and tissues of the 
body may have an influence, but this is only in producing those con- 
ditions of environment which render the activities of the destructive 
agents efficient in their action upon tooth tissues. Though the enamel 
and dentin are passive, we can understand the phenomena of caries 
only as we understand the structure of the tissues; and not only must 
the treatment of caries be based upon a knowledge of the structure 
of the tissues, but the mechanical execution of the treatment is facili- 
tated by that knowledge. In the preparation of cavities the arrange- 
ment of the enamel wall is determined by our knowledge of the direction 
of enamel prisms in that locality, and to a certain extent the position 
of the cavity margins must be governed by our knowledge of the structure 

1 In the preparation of this material I am indebted to Dr. G. V. Black for the use of his large 
and valuable collection of microscopic slides, and for much advice and many suggestions. 

(56) 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



57 



of the enamel. In the execution of the work a minute knowledge of the 
direction of enamel rods becomes the most important element in rapidity 
and success of operation. 

From the standpoint of comparative anatomy, the teeth are found 
to be not a part of the osseous system, but appendages of the skin, 
and are to be compared with such structures in the body as the nails 
and the hair. The teeth are a part of the exoskeleton, and their rela- 
tion to the bones of the endoskeleton is entirely secondary, for the pur- 
pose of strength,, the bone growing up around the tooth to support it. 

If we examine the skin of such an animal as the shark, we find the 
entire surface covered with small calcified bodies which are really 
small simple cone-shaped teeth The mouth cavity is to be regarded, 



Fig. 31 



1' 


3301 


^r^^^=--^^ 


M 


>j 











Shark's skull (Lamna cornubica), showing succession of teeth. 



when viewed in the light of its development, as a part of the outside 
surface of the body which has been enclosed by the development of the 
neighboring parts, and the dermal scales or rudimentary teeth which 
were found in the skin covering the arches which form the jaws have 
undergone special development for the purposes of seizing and masti- 
cating the food. In the simplest forms there is only a development 
in size and shape of these scales, and they are supported only by the 
connective tissue which underlies the skin. These teeth are easily torn 
off in the attempt to hold a resisting prey, and, as in the shark, they are 
constantly being replaced by new ones (Fig. 31). In the more highly 
developed forms there is a growth of the bone of the arch forming the jaw 
upward around the bases of these scale-like teeth, to support them 
more firmly and render them more useful. 



58 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



If we compare the structure of the hair with that of the tooth, we 
find, in the case of the hair, a horny structure composed of epithelial 
cells resting upon a papilla of connective tissue; in the case of the tooth, 
a calcified structure formed by epithelial cells resting upon a papilla 
of connective tissue which is also partially calcified. 

The relation of the bones of the jaws to the teeth is entirely a secondary 
and transient one. The bone grows up around the roots of the teeth to 
support them, and is destroyed and removed with the loss of the teeth 
or the cessation of their function. In this way the development of the 



Fig. 32 






Changes in the mandible with age; buccal and lingual view. 

alveolar process takes place around the temporary teeth; all of this bone 
surrounding their roots is absorbed and removed with the loss of the 
temporary dentition, and a new alveolar process grows up around the 
roots of the permanent teeth as they are formed. This development of 
bone around the roots of the teeth leads to the changes in the shape of 
the body of the lower jaw, increasing the thickness above the mental 
foramen and the inferior dental canal. When the teeth are finally lost 
this bone is again removed and the body of the jaw is reduced in thick- 
ness from above downward (Fig. 32). These phenomena are of im- 
portance in their bearing upon the causes and treatment of diseased 
conditions of the teeth, particularly those which involve the supporting 
tissues. 



ENAMEL 59 

Dental Tissues. — The human teeth are made up of four tissues 
(Fig. 33): 

1. The enamel covers the exposed portion of the tooth, or crown, 
and gives the detail of crown form. Its function is to protect the tooth 
against the wear of friction. 

2. The dentin forms the mass of the tooth and determines its class 
form, the number of cusps and the number of roots being indicated by 
the dentin form. 

3. Cementum covers the dentin beyond the border of the enamel, 
overlapping it slightly at the gingival line and forming the surface of 
the root. Its function is to furnish the attachment of the fibers of the 
peridental membrane, which fastens the tooth to the bone. 

4. The pulp, or soft tissue, filling the central cavity in the dentin 
is the remains of the formative organ which has given rise to the dentin. 
Its functions are the formation of dentin and a sensory function. 

In describing the structure of the teeth and the arrangement of the 
structural elements of the tissues directions are described with reference 
to three planes: 

The mesio-disto-axial plane, a plane passing through the centre of the 
crown from mesial to distal and parallel with the long axis of the tooth. 

The bucco-linguo-axial plane, a plane passing through the centre of 
the crown from buccal to lingual and parallel with the long axis of the 
tooth. 

The horizontal plane, at right angles to the axial planes. 

The Supporting Tissues. — The human teeth are supported on the 
maxillary bones, their alveolar processes growing up around the roots of 
the teeth, so that the roots fit into the holes in the bone. The calcified 
structures of the tooth and the bone are not, however, united, but the 
roots are surrounded by a fibrous membrane, the peridental membrane, 
or pericementum, which fastens the tooth to the bone. 



ENAMEL 

The enamel differs from all other calcified tissues in the nature of 
the structural elements of which this tissue is made up, in the degree 
of calcification, and in origin, being the only calcified tissue derived 
from the epiblast. 

The enamel is formed from an epithelial organ derived from the 
epithelium of the mouth cavity and indirectly from the epiblastic germ 
layer, while all other calcified tissues are products of the mesoblast. 
In the case of bone and dentin the formative tissue is persistent. It 
is possible in bone at least, therefore, to have degenerative and regen- 
erative changes, or the removal of part of the calcium salts and their 
replacement through the agency of the formative tissue; while in the 



60 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

Fig. 33 




Ground section of a canine: E, enamel; Cm, cementum; D, dentin; Pc, pulp chamber; De, 
dento-enamel junction; Ed, enamel defect; G, junction of enamel and cementum at the gingival 
line; Gt, granular layer of Tomes. (Reduced from photomicrograph made in three sections.) 



ENAMEL 61 

enamel no such regenerative change is possible, as the formative tissue 
disappeared when the tissue was completed and before the eruption of 
the tooth. 

The enamel is the hardest of human tissues. Chemically it is com- 
posed of the phosphates and carbonates of calcium and magnesium and 
a very small amount of the fluorides, water, also a very small amount 
of organic matter if any. 1 The enamel in the natural condition, bathed 
in the fluids of the mouth, contains a considerable amount of water. 
If dried at a little above the boiling point of water, it gives up part 
of it and shrinks considerably, so as to crack in fine checks. If heated 
almost to redness, it suddenly gives off from 3 to 5 per cent, (of the 
dry weight) of water with almost explosive violence. These facts were 
demonstrated some years ago by Charles Tomes, 2 and account for most 
of what was formerly recorded as organic matter in old analyses. 

If we observe under the microscope the action of acids upon thin 
sections of enamel, when the inorganic salts are entirely removed, the 
structure of the tissue vanishes, there being no trace of organic matrix 
left as in the case of bone or dentin. In the growth of bone and den- 
tin the formative tissue produces first an organic matrix in the form 
of the tissue, and into this the inorganic salts are deposited, combining 
with the organic substances of the matrix. This union is compara- 
tively weak, however, for by the action of acids the combination is 
broken up and the inorganic salts are dissolved; or by heat the organic 
matter is removed, and in either case the form of the tissue will be 
maintained. 

In the case of the enamel, the formative organ produces organic 
substances containing inorganic salts, and the substances are arranged 
in the form of the tissue after the manner of a matrix; but finally under 
the action of the formative organ all of the organic matter is removed 
and substituted by inorganic salts, whatever organic matter is found in 
the fully formed tissue being the result of imperfect execution of the 
plan. 

The enamel is composed of two structural elements, the enamel rods, 
or prisms, sometimes called enamel fibers, and the inter prismatic or 
cementing substance, both of which are calcified. It is to the arrange- 
ment of these structural elements that the characteristics of the tissue 
with which we are most concerned in operative procedures are due. 

1 Von Bibra gives the following analysis of enamel: 

Calcium phosphate and fluorid 89.82 

Calcium carbonate 4.37 

Magnesium phosphate 1 . 34 

Other salts 0.88 

Cartilage 3.39 

Fat 0.20 

Total organic 3.59 

Total inorganic 96.41 

2 Journal of Physiology, 1896. 



62 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



While both the prisms and interprismatic substance of the enamel 
are calcified, or, better, composed of inorganic salts, the two substances — 
that is, the substance of the rods and the substance between the rods 
— show markedly different properties both chemical and physical. If 
treated with acid, the interprismatic substance is acted upon more 
rapidly than the rods, so that the latter become more conspicuous. By 
this means sections of the enamel may be etched to render it easier to 
study the direction and arrangement of the rods. If the action of the 
acid is carried far enough, the rods will fall apart before they are them- 
selves entirely dissolved. Fig. 34 is from the debris in a carious cavity, 
and shows rods isolated by the action of the acids of caries. 



Fig. 34 




Enamel rods isolated by caries. (About 465 X) 



The interprismatic substance is not as strong as the rods, so that in 
splitting or breaking the enamel the tissue separates on the lines of the 
cementing substance, occasionally breaking across a few rods but fol- 
lowing their general direction, the lines running between rods, not at 
their centres. 

In cleaving the enamel the chisel does not enter the tissue sepa- 
rating rod from rod, but the edge engages with the surface, and the 
force applied at an acute angle with the direction of the rods fractures 
the tissue in the lines of least resistance. If the edge be keenly sharp, 
it will enter the tissue slightly, and then the bevel acts as a wedge in 
addition to the force applied to the shaft of the instrument; but if the 
edge be dull, it will rest across the ends of many rods, will not engage 
with the surface, and the force applied will break and crumble the 
tissue, but will not cleave it. 



• • ENAMEL . 63 

The enamel rods, or prisms, are long, slender prismatic rods or 
fibers, five- or six-sided, pointed at both ends, and alternately expanded 
and constricted throughout their length. They are from 3.4 to 4.5 
microns 1 in diameter, some of them apparently reaching the entire 
distance from the surface of the dentin to the surface of the enamel; but 
as the diameter of the rods is the same at their outer and inner ends, 
and as the crown surface is much greater than the surface of dentin 
covered by enamel, there are many rods which do not extend through 
the entire thickness. These short rods end in tapering points between 
the converging rods which extend the entire distance. To express 
this in terms of development: as the formation of enamel begins at 
the surface of the dentin, the increasing area of crown surface requires 
more ameloblasts, and as new ameloblasts take their place in the layer 
the formation of new enamel rods begins between the rods which were 
previously forming. These short rods are most numerous over the 
marginal ridges and at the points of the cusps, and will be considered 
more fully in connection with those positions. 

In ground sections cut at right angles to the direction of the rods 2 
the tissue has the appearance of a mosaic floor, the outline of the rods 
being more distinct if they have been marked out by treating the section 
slightly with acid (Fig. 35). In longitudinal sections (Fig. 36) the sides 
of the rods are not smooth and even like the sides of a lead pencil, but 
are alternately expanded and constricted. They are well illustrated by 
taking balls of soft clay and sticking them together one above another 
to form a rod, then putting a number of rods together so that by mutual 
pressure they take hexagonal forms. This illustrates also the manner 
of growth of the tissue in formation. The expansions and constrictions 
can be seen in rods that have been scraped from a cleaved surface of 
enamel, but better by isolating rods bv the slight action of dilute acid 
(Fig. 37). 

In the construction of the tissue the rods are so arranged that the 
expansions of one rod come opposite to the expansions in the adjoining 
rods, and do not interlock with their constrictions. This arrangement 
leaves alternately a greater and a less amount of cementing substance 
between them. 

When observed under the microscope, the enamel rods show a char- 
acteristic appearance of light and dark lines running across them. 
These markings are similar to the striations of voluntary muscle fibers, 
and are described as the striation of the enamel. It is seen not only in 
isolated rods (Fig. 34), but also in sections ground in their direction (Fig. 
38). This appearance of striation in the enamel is caused by the alter- 

1 A micron is the unit of microscopic measurement, and is equal to one one-thousandth of a 
millimeter. 

2 In describing the direction of enamel rods they are always considered as extending from the 
dentin to the surface, and the angle is formed at the surface of the dentin with the locating plane, 
either horizontal or axial. 



64 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



nate expansions and constrictions of the rods refracting the light like a 
lens. In sections the expansions in adjoining rods are opposite to each 



Fig. 35 




Transverse section of enamel rods. (About 80 X) 

other, the difference in the refracting power of the prismatic and inter- 
prismatic substances producing the same effect. 

Fig. 36 




Enamel rods in thin etched section. (About 800 X) 



The appearance of striation is the record in the fully formed tissue 
of the manner of growth, each dark stripe, or expansion, in a rod repre- 



ENAMEL 



65 



senting a globule of partially calcified material. The ameloblasts 
build up the rods by the addition of globule after globule, surrounding 



Fig. 37 




Enamel rods isolated by scraping. (About 800 X) 

them with a cementing substance and completing the calcification of 
both. In this sense the striation of the enamel may be said to record 
the growth of the individual rods. 



Fig. 38 













Enamel showing striation. (About 1000 X) 

While the enamel is a very hard substance when its structure is com- 
plete and perfect, its most striking physical characteristic is a tendency 
5 



66 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



to split or crack in the direction of its structural elements when a break 
has been made in the tissue. While it is difficult to cut across the rods 
or make an opening on a perfect surface, if a break has been established 
it is comparatively easy to split off the tissue from the sides of the opening 
when the rods lie parallel with each other. Fig. 39 shows a field of 
enamel illustrating the way in which the tissue splits or cleaves in the 
direction of the rods. 

Upon the axial surfaces the enamel rods are usually straight and 
parallel with each other, except where there has been some flaw or 
disturbance in development; but upon the occlusal surface, although 
sometimes straight, they are very often much twisted and wound around 
each other, especially at their inner ends. This difference in the arrange- 



Fig. 39 




Enamel showing direction of cleavage. (About 70 X) 



ment of the rods causes the greatest difference in the feeling of the 
tissue under cutting instruments. Such a specimen of enamel as shown 
in Fig. 40 can be cut away easily, the tissue breaking through to the 
dentin and splitting off in chunks; while a specimen like Figs. 41 and 
42 will, not cleave if supported upon sound dentin. If the outer ends 
of the rods are straight, they will split part way to the dentin (Fig. 42); 
but where they begin to twist around each other they will break across 
the rods. If the dentin is removed from under such enamel, it will 
break in an irregular way through the gnarled portion. 

From a study of the arrangement of the enamel rods in the forma- 
tion of the crown it is apparent that the plan is such as to give the greatest 
strength to the perfect structure, and may be likened to an arch. At 
the gingival border the rods are short and are inclined apically 6 to 10 



ENAMEL 

Fig. 40 



67 




Straight enamel rods. (About 80 X) 
Fig. 41 




Gnarled enamel. (About 80 X) 



68 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



centigrades 1 (20 to 35 degrees) from the horizontal plane. These short 
rods are overlapped for a short distance by the cementum. This inclination 
grows less and less, and at some place in the gingival half of the middle 
third of the surface they are in the horizontal plane. At this point they 



Fig. 42 




Gnarled enamel. (About 50 X ) 



are also usually perpendicular to the surface of the dentin. Passing 
from this point they become inclined more and more occlusally from the 
horizontal plane, at the junction of the occlusal and middle thirds about 8 
to 12 centigrades (28 to 40 degrees) in bicuspids and molars, and 8 to 18 
centigrades (28 to 65 degrees) in incisors and canines. In the occlusal third 



1 In the centigrade division the circle is 
divided into one hundred parts, each called 
a centigrade. One centigrade is equal to 3.6 
degrees of the astronomical circle, 25 centi- 
grades to 90 degrees, 12 centigrades to 45 
degrees. The cut gives a comparison of the 
two systems of measuring angles. 



270 




180 
Centigrade division. 



ENAMEL 



69 



the inclination increases rapidly, and often the outer ends of the rods 
are inclined more than the inner ends. Over the point of the cusps 
and the crest of the marginal ridges the rods reach the axial plane, 
though they are often very much twisted about each other in the inner 
half of their length. This position does not always correspond with the 
highest point of the cusp, but is inclined slightly axially from that posi- 
tion, and corresponds with the highest point of the dentin cusp. 



Fig. 43 




Diagram of enamel rod directions, from a photograph of a bucco-lingual section of an upper biscupid. 



Passing down the central slope of the cusp, or ridge, the rods become 
again inclined away from the axial plane toward the groove, or pit, 
leaning toward each other where the two plates meet. The degree of 
inclination of the rods on the central slope of the cusps depends upon the 
height of the cusps ; the higher the cusp the greater the inclination from 
the axial plane. Fig. 43, a diagram from a photograph of a bucco- 
lingual section of an upper bicuspid shows the plan of arrangement and 
illustrates the arch principle in the construction. 

In the study of longitudinal sections of the teeth, one of the most 
conspicuous structural features is the stratification bands, or brown 
bands of Retzius. These bands are not parallel with either the outer 
surface of the enamel or the dento-enamel junction. They begin at the 
tip of the dentin cusps and sweep around in larger and larger zones. 



70 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



These stratification bands are better seen in comparatively thick sec- 
tions, and are caused by the varying amount of pigment deposited with 
the calcium salts in the development of the tissue. They record the 
growth of enamel of the crown as a whole, as each line was at one time 
the surface of the enamel cap. These stratifications, or, better, incre- 
mental lines, are shown in Figs. 44 to 46. 



Fig. 44 




Stratification of enamel; the cusp of a biscupid: De, dento-enamel junction; Ed, enamel defect 
showing in the heavy stratification band; Iff, interglobular spaces in the dentin. (About 40 X) 



At the time the rod at A (Fig. 45) was completely formed the rod at 
B was just beginning to form at its dentinal end. From this it would 
seem that any structural defect due to imperfect development would not 
follow the direction of the enamel rods from the surface to the dentin, 
but would follow the stratification lines; and if these structural defects 
influenced the penetration of caries, we should expect to have the direc- 
tion of penetration modified. Fig. 44 shows a structural defect in the 



ENAMEL 



71 



enamel over a cusp following the stratification band, and it will be 
noticed also that there is a structural defect in the dentin at a corre- 
sponding position. 



Fig. 45 




Incisor tip showing stratification or incremental lines. Rods at .4 were fully formed at the 
time the rods at B were beginning to form. (About 50 X) 



HISTOLOGICAL REQUIREMENTS FOR STRENGTH IN ENAMEL 

WALLS 



1. The enamel must be supported upon sound dentin. 

2. The rods which form the cavosurface angle must run uninter- 
ruptedly to the dentin and be supported by short rods, with their inner 
ends resting on the dentin and their outer ends abutting upon the cavity 
wall, where they will be covered in by the filling material. 

3. That the cavosurface angle be cut in such a way as not to expose 
the ends of the rods to fracture in condensing the filling material against 
them. 

The first step, then, in the preparation of an enamel wall is to deter- 



72 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



mine the direction of the enamel rods by cleavage with a chisel or 
hatchet. 

In Figs. 47 and 48, No. 1 shows an enamel wall after cleaving the 
enamel with a hatchet. It will be noticed that the split has not followed 
the direction of the rods exactly, but has broken across them, slivering the 
rods as wood slivers in splitting. This would cause in the cut surface 
a whitish, opaque appearance. The plane of the enamel wall should be 
extended so as to form a small angle with the plane of the dentin wall, 
by shaving the surface with a very sharp hand instrument. No. 2 shows 
the same wall after it has been extended somewhat; but it will be seen 
that it has not been extended enough, for the rods forming the sur- 
face at A do not reach the dentin, but run out at B on the cavity wall, 
and that piece would chip out in packing against it or if force came upon 

Fig. 46 







\ 




Enamel showing both striation and stratification. (About 80 X) 

the surface afterward. The angle should be extended so as to produce 
the plane shown in No. 3; then the cavosurface angle may or may not 
be bevelled as the position demands. 

In some positions, as on the axial surfaces, it is not possible to ex- 
tend the plane of the entire enamel wall as described; all that can be 
done is to shave the cut surface, leaving the wall in the direction of the 
enamel rods, and then the margin is strengthened by bevelling the cavo- 
surface angle, so that the rods forming the margin are supported by at 
least a few rods which are covered by filling material. 

In cutting out the fissures on the occlusal surfaces of molars and 
bicuspids, the rods are inclined centrally from the axial plane, as seen 
in Fig. 49. In opening a fissure the lines of cleavage will not be in 
the axial plane, but sloping inward toward the body of the cusp, in the 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS 73 




rH G .- 


s 


=3 *" 


O 


* "3 

— ,Q 


*x 






oi £ 


c a 


S o 


a> © 


X! 


v. T3 


2 < 



74 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 







Preparation of enamel wall in gnarled enamel: 1. Enamel wall as cleaved, showing breaking 
across rods and slivering at a. 2. Wall as smoothed but not extended to remove short rods 
whose inner ends are cut off at b. 3. Wall extended and trimmed to a position of strength. 
D, dentin; De, dento-enamel junction ; c, cavo-surface angle; b, point where inner ends of 
rods are cut off; a, slivering of the tissue. (About 80 ><.) 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS 



75 



direction indicated by the direction of the cracks in Fig. 49. The outer 
ends of the enamel rods must be shaved away, to bring the plane of 
the enamel wall parallel with the dentin wall or into the axial plane. 
When this has been done a strong margin has been formed, for the 
rods which form the point of the cavosurface angle are supported by 
the piece A, B, C (Fig. 50), made up of rods resting upon sound dentin 



Fig. 49 





V 



Occlusal fissure in an upper bicuspid, showing direction of rods. (About 80 X) 



and covered by the filling material. Often the angle will be too sharp, 
however, and the cavosurface angle should usually be bevelled to pro- 
tect the margin from accident. This illustration may be taken as 
typical of occlusal cavities. 

Fig. 51 shows a cavity prepared in the buccal surface of an upper 
molar. The occlusal margin is placed in the occlusal half of the middle 
third, and the gingival margin in the gingival half of the gingival third 



76 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



of the surface. In the occlusal wall the rods are inclined occlusally 
about 8 centigrades (28 degrees) from the horizontal plane. After cleav- 
ing, the broken and slivered rods should be shaved away, but the angle 
cannot be increased without making the margin of filling material too 



Fig 




Preparation of enamel walls in occlusal fissure cavities (the same as Fig. 49). 



thin; the rods forming the margin should therefore be protected by bevel- 
ling the cavosurface angle. At the gingival wall the rods are inclined 
apically from the horizontal plane about 6 centigrades (20 degrees). The 
wall should be shaved in that plane, increasing the angle a little, and 
the cavosurface angle should be bevelled. Fig. 52 shows the occlusal 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS 11 



Fig. 51 




Preparation of enamel walls in a buccal cavity in a molar : G, gingival wall ; 0, occlusal wall 

(About 70 X.) 



78 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

enamel wall alone, after cleaving and trimming into form. Such enamel 
walls may be taken as typical of axial surface cavities, the angle of the 

Fig. 52 




2. Wall as trimmed. 
Preparation of occlusal wall of Fig. 51. (About 70 X ) 

enamel with the dentin wall being determined by the direction of the 
enamel rods in the position where the margin is laid. 

Grooves, fissures, and pits are always positions of weakness, and 
when a cavity approaches a groove or pit a good margin, histologically, 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS 79 

cannot be prepared without cutting beyond it. Fig. 53 shows an 
occlusal fissure in a bicuspid, which illustrates the conditions of structure 
characteristic of these positions. The rods are inclined toward the 
fissure, and between the bottom of the fissure and the dentin are very 
irregular. If a cavity wall were made to approach this fissure from 
the lingual side, so as to come to the dotted line, the wall would have 
to be inclined 6 to 8 centigrades (20 degrees to 28 degrees) from the axial 
plane toward the fissure, and then the cavosurface angle bevelled, when 
the conditions would be similar to those in the wall of an axial surface 
cavity, and not as strong as the location requires. Not only is this true, 



Fig. 53 




Structure of enamel about a fissure: B, buccal side; L, lingual side. (About 70 X) 



but it also leaves a vulnerable point next to the margin of the filling — 
a point of liability. Cutting just beyond the fissure, the wall may be 
left in the axial plane and have an ideally strong margin, and the point 
of liability is removed. To state the conditions in general terms, a 
strong margin is more easily obtained where enamel rods are inclined 
toward the cavity than where they are inclined away from the cavity. 

The points of cusps and the crests of marginal ridges are positions of 
strength in the perfect tissue; but when a cavity margin approaches 
them they become points of weakness, because it is impossible to sup- 
port properly the rods which form the margin. Over the marginal 



80 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



ridges are many short rods which do not reach the dentin, and these 
are usually much twisted about each other, so as to form the strongest 
possible keystone in the perfect structure. In preparing a margin 
in such a position it is impossible to have the rods which form the 
margin reach the dentin with their inner ends, and these short rods 
are sure either to break in completing the operation or to break out 
later. The arrangement of enamel rods in such positions is to be borne 



Fig. 54 




Bucco-lingual section of upper bicuspid; enamel is broken from grinding: A to B, area of 
weakness for enamel margins. (About 20 X) 



in mind, especially w T hen extending approximal cavities in incisors 
toward the lingual side and in large pit cavities in incisors. A similar 
condition is found over the points of the cusps. Fig. 54 shows a bucco- 
lingual section of an upper bicuspid. It will be noticed that the rods 
forming the point of the cusp are not in the axial plane, and do hot 
reach the tip of the dentin cusp, but reach the dentin a little way 
down on the outer slope. The enamel covering the tip of the dentin 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS 81 

contains many short rods, and they are very much twisted about each 
other, so that the area from A and B to the point of the cusp is an area 
of weakness for cavity margins. If the margin reaches this area, the 



Fig. 55 




Enamel over tip of dentin cusp: D, dentin cusp. (About 80 X) 



cusp must be cut away and the enamel wall carried out in the hori- 
zontal plane. Fig. 55 shows this area more highly magnified, and 
illustrates the structure. It will be noticed that, in grinding, some of 
the short twisted rods have broken out of the section. 
6 



82 



DEXTAL HISTOLOGY AND OPERATIVE DENTISTRY 



Fig. 56 shows the tip of an incisor in labiolingual section, and is of 
interest in relation to the formation of margins in step cavities in in- 
cisors. The tip of this tooth has been worn off in use. The illustration 
shows that the great inclination of the rods toward the axial plane in 
the occlusal third of the incisors is such as to bring the wear almost at 
right angles to the direction of the rods. 



Fig. 56 




Tip of an incisor. (About 50 X) 



DENTIN 

The structure of dentin is of comparatively little interest in the pres- 
ent consideration, as its histological forms do not directly influence 
the cutting of the tissue in the excavation of cavities. Its histological 
forms have, however, much to do with the penetration of caries and 
with other considerations which are of importance to the intelligent 
practice of operative dentistry. 



DENTIN 



83 



Dentin belongs to the connective-tissue group, and is made up of 
a solid organic matrix impregnated with about 72 per cent, of inorganic 
salts 1 and pierced by minute canals or tubules, which radiate from a 
central cavity which contains the remains of the formative organ, or 
pulp. The minute canals, or dentinal tubules, are occupied in life 
by protoplasmic processes from the odontoblastic cells which form the 



Fro. 57 




Dentin at dento-enamel junction, showing tubules cut longitudinally: Dt, dentinal tubules; 
D, dentin matrix. (About 760 X) 



outer layer of the pulp. Dentin contains two kinds of organic matter, 
the contents of the tubules and the organic basis of the matrix. The 
dentin matrix, after the removal of the calcium salts by acids, yields 
gelatin on boiling and resembles the matrix of bone, reacting in a similar, 
though not identical, way with staining agents. The portion of the 



Von Bibra gives the following analysis of dentin : 

Organic matter 27.61 

Fat 0.40 

Calcium phosphate and fluorid 66.72 

Calcium carbonate 3 . 36 

Magnesium phosphate 1 . 08 

Other salts 0.83 



84 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



matrix immediately surrounding the tubules shows different chemical 
characteristics from the rest of the matrix, resembling elastin, and 
resisting the action of strong acids and alkalies after the rest of the 
tissue has been destroyed. This portion of the matrix surrounding the 
tubules and lying next to the fibrils is known as the sheaths of Neumann. 

The dentinal tubules are from 1.1 to 2.5 microns in diameter, and 
are separated from each other by a thickness of about 10 microns of 
dentin matrix. This is fairly uniform throughout the dentin. The 
character of the tubules is different in the crown and root portions. 

In the crown the tubules branch but little through most of their 
course; but in the outer part, close to the enamel, they branch and 
anastomose with each other quite freely. Fig. 57 shows a field of dentin 



Fig. 58 




Dentin showing tubules in cross-section: Dt, dentinal tubules; D, dentin matrix; S, shadow 
of sheaths of Neumann. (About 1150 X) 



just beneath the enamel, as seen with a high power, and shows the 
diameter of the tubules, their branching, and the amount of matrix 
between one tubule and the next. The relation of one tubule to each 
other is shown also in sections cut at right angles to their direction 
(Fig. 58). In the crown portion the tubules pass from the pulp chamber 
to the dento-enamel junction in sweeping curves, so as to enter the pulp 
chamber at right angles to the surface, and end next to the enamel at 

right angles to that surface. This produces S- or F-shaped 



or 



curves, which are known as the primary curves of the tubules. Through- 
out their course the tubules are not straight, but show a great many 
wavy curves, known as the secondary curves. These appear as waves 



DENTIN 



85 



when seen in longitudinal sections, but are really the effect of an open 
spiral direction, as is seen by changing the focus of the microscope in 
studying sections cut at right angles to the direction of the tubules. 
The branches throughout their length are few and small, and are given 
off at an acute angle to the direction of the tubule; but just before the 
enamel is reached the tubules fork and branch, producing an appearance 
similar to the delta of a river. These branches are given off from the 
tubules for some little distance back from the enamel, and they anas- 
tomose with other tubules very freely. The branching of the tubules 
in their outer portion causes the spreading of caries just beneath the 



Fig. 59 




Crown of a molar, mesio-distal section, showing penetration of caries: A, caries penetrating dentin; 
B, line of abrasion; P, pulp chamber. (About 20 X) 



enamel, the microorganisms growing through the branches from tube 
to tube, and so spreading sideways beneath the enamel plates, and then 
penetrating the dentin in the direction of the tubules. Fig. 59 shows 
the penetration of caries in the dentin. It will be noticed that in decay 
starting at the contact point there has been more spreading under the 
enamel than in that starting at the gingival line, but in both positions 
the penetration has followed the direction of the tubules. 

In the root portion the tubules pass out from the pulp canals at right 
angles to the long axis of the tooth and pass directly out to the cemen- 
tum, showing only the secondary curves. Throughout their course they 
give off a great many fine branches passing through the matrix in all 



86 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

Fig. 60 




Dentin from the root, showing tubules cut longitudinally. (About 700 X ) 



Fig. 61 




Dento-enamel junction. (About 70 X ) 



DENTIN 



87 



directions from tubule to tubule. These branches are so numerous that 
in sections which have been mounted in such a way as to leave air in 
them, or if the tubules have been filled with coloring matter, they give 
the impression of looking through a hazel bush; or they may be likened 
to the fine rootlets of a plant. These fine branches are shown in Fig. 
60, and the character of the dentin in the root portion is to be compared 
with that in the crown portion as shown in Fig. 57. The outermost 
layer of the dentin next to the cementum contains many small irregular 



Fig. 62 



Rk. 


1 


' m *' 


. 




" A. 


*;0 








* '.«• *-i '■ •> £ t . 




"V 1" j£ *'»^VV .; 


. 



Tg 



¥ 



Interglobular spaces in dentin: Ig, first line of interglobular spaces; Ig', second line of inter- 
globular spaces. (About 30 X ) 



spaces, which connect with the dentinal tubules and give to the tissue 
when seen with low powers a granular appearance. This layer was 
first described by John Tomes as the granular layer, and has since 
been usually called the granular layer of Tomes. The spaces of the 
granular layer are probably filled by the enlarged ends of the den- 
tinal fibrils. The same appearance is sometimes seen beneath the enamel, 
but is never as well marked as next to the cementum. 

The dentin at the dento-enamel junction seldom presents a smooth 
surface, but the inner surface of the enamel plate shows rounded pro- 
jections, between which the dentin extends. In sections this gives to 



88 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



the dentoenamel junction a scalloped appearance, as shown in Fig. 61; 
and often the deceptive appearance of the dentinal tubules penetrating 
for a short distance between the enamel rods. 



Fig. 63 




Granular layer of Tomes: L, lacunae of cementum Gt, granular layer of Tomes; Ig, inter- 
globular spaces. (About 200 X ) 



In many specimens made by grinding dried teeth large irregular 
spaces are very conspicuous in the dentin. They usually occur in lines 
or zones at about uniform depth from the surface. These have been 
called the interglobular spaces. They are really not spaces at all, but 
are areas of imperfect development in which the dentin matrix has 
not been calcified. The dentinal tubules pass through them without 
interruption. In a dried specimen the organic matrix shrinks, and the 
resulting space becomes filled with the debris of grinding, so as to give 
the appearance of black spaces. Fig. 62 shows two quite distinct layers 
of interglobular spaces, the second much more marked than the first; 
and in the enamel at a position corresponding to the first is seen an 
imperfection of structure marked by the very dark stratification band. 
This is shown best in the region of the cusp (Fig. 44) from the same 
section. Interglobular spaces in the root portion of the dentin are 
shown in Fig. 63, close to the granular layer of Tomes. 



PULP 



89 



The formation of dentin is not complete at the time of eruption of 
the tooth, but continues for an indefinite period, thickening the layer of 
dentin at the expense of the pulp. When the typical amount of dentin 
has been formed the growth ceases, and does not begin again unless 
excited by some irritation to the pulp or the pulp of some other tooth 
of the same side, which leads to the formation of secondary dentin. 
Secondary dentin is never as perfect in structure as primary dentin; 
the tubules are smaller, fewer, and much more irregular. Often in 
ground sections several periods of formation can be determined by 
differences of structure, each deposit becoming successively more and 
more imperfect in structure. This is shown in Fig. 64. 



Fig. 64 




A 



Secondary dentin: A, margin of primary dentin, showing a few of the tubules continuing 
into the secondary dentin; P, pulp chamber. (About 80 X) 



PULP 



The dental pulp is the soft tissue occupying the central cavity of the 
dentin. It is made up of embryonal connective tissue and contains a 
large number of bloodvessels and nerves. Like all connective tissues, 
the intercellular substance is large in amount and the cells are widely 
scattered in this soft, jelly-like tissue, which contains but few fibers. 
We recognize four kinds of cells in the pulp— the odontoblasts, forming 



90 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



the outer surface of the pulp next to the dentin; and round, spindle- 
shaped, and stellate connective-tissue cells. 

^ Arrangement of Cells.— The odontoblasts are tall columnar cells, some- 
times club-shaped, and in older tissues, which have ceased to be func- 
tional, sometimes becoming almost spherical. They form a continuous 
layer over the entire surface of the pulp, being everywhere in contact 
with the dentin. The layer has been called the membrana eboris, or the 
"membrane of the ivory." 

The nuclei of the odontoblasts are large and oval, containing a large 
amount of chromatin, and are very different from the nuclei of ordinary 
connective-tissue cells. 

Fig. 65 



F 

N 



:# 












Odontoblasts. The section cuts obliquely through the odontoblasts: F, fibrils; N, nuclei of 
odontoblasts; N f , nuclei of connective-tissue cells; W, layer of Weil, not well shown. (About 80 X "> 

Three kinds of processes have been described in connection with the 
odontoblasts : 

1 . The dentinal fibril processes, or fibers of Tomes. These are long, 
slender protoplasmic processes projecting from the dentin end of the 
cell into a dentinal tubule, and running through the tubule to the outer 
surface of the dentin. Usually there is but one fibril extending from 
each odontoblast, but sometimes two can be seen, extending into two 
tubules. These fibrils can be demonstrated in decalcified sections or 
by removing the pulp from a recently extracted tooth by cracking the 
tooth and carefully lifting the pulp out of the pulp chamber, and then 
either teasing or sectioning. Fig. 65 shows the fibrils projecting from 
the surface; but in this section the cut was not in the direction of the 
long axis of the odontoblasts, but obliquely through them. Fig. 66 



PULP 



91 



(from a photograph by Rose) shows the form of the odontoblasts in a 
young tooth in which formation of dentin is actively progressing, with 
the fibrils in the dentinal tubules. 

2. Lateral processes projecting from the sides of the cells and uniting 
one with another in the formation of the layer. 

3. Pulpal processes, projecting from the pulpal ends of the odonto- 
blasts into the layer of Weil. 

The odontoblasts, as the name indicates, are the dentin-forming 
cells. They superintend the formation and calcification of the dentin 
matrix, the fibril being left behind surrounded by the formed tissue. 
Whether the fibrils have any share in the formation and calcification of 
the dentin matrix has been a matter of controversy. 



Fig 




Odontoblasts and forming dentin: E, forming enamel; D, forming dentin; O, odontoblasts; 
Dp, body of dental papilla. (From photomicrograph by Rose.) 



The relation of the fibrils to the transmission of sensation is also a 
matter of dispute; but at present the weight of evidence is that they 
in some way transmit impressions to the sensory nerves of the pulp. 

Just beneath the layer of odontoblasts is a zone which contains very 
few connective-tissue cells. In thin sections, especially in the body of 
the pulp, this appears as a clear layer about half as thick as the layer 
of odontoblasts. It is known as the layer of Weil. Just beneath the 
layer of Weil the connective-tissue cells are especially numerous and 
form a more or less distinct layer of closely placed cells. In the rest of 
the body of the pulp the cells are about uniformly distributed throughout 



92 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



the intercellular substance. These connective-tissue cells are of the 
characteristic forms, rather small, containing a small but deep-staining 



Fig. 67 







Diagram of the bloodvessels of the pulp. (Stowell.) 
Fig. 68 



"5? * 



* # 










l ** 







i 



W J rt 





A pulp bloodvessel, showing the thin wall: C, blood corpuscles in the vessel; Bl, bloodvessel 
wall showing nuclei of endothelial cells; N, nuclei of connective-tissue cells in the body of the pulp; 
I, intercellular substance, showing a few fibers. (About 200 X ) 

nucleus, the protoplasm stretching out into slender projections in two 
directions to form the spindle cells, or in more than two directions to 



PULP 93 

form the stellate cells. The stellate forms are more common in the 
body of the pulp, the spindle form in the canal portions. The round 
cells are comparatively few in number, and are probably young cells 
which have not yet acquired the adult form. 

The Bloodvessels of the Pulp. — The blood supply of the pulp is extremely 
rich, several arterial vessels entering in the region of the apex of the root, 
often through several foramina. These large vessels extend occlusally 
through the central portion of the tissue, giving off many branches which 
break up into a very close and fine capillary plexus (Fig. 67). From the 
capillaries the blood is collected into the veins, which pass apically through 
the central portion of the tissue. A very striking peculiarity of the blood- 
vessels of the pulp is the thinness of their walls. Even the large arteries 
show scarcely any condensation of fibrous tissue around them to form 
the usual adventitious layer, and usually contain but a single involuntary 
muscle fiber representing the media, while the walls of even the large 
veins are made up of only the single layer of endothelial cells forming 
the intima, and are in structure like large capillaries (Fig. 68). This 
peculiarity of the bloodvessel walls is of great importance, as it renders 
the tissue especially liable to such pathological conditions as hyperemia 
and inflammation. 

The Nerves of the Pulp. — Several comparatively large bundles of medul- 
lated nerve fibers, containing from six or eight to fifteen or twenty 
fibers, enter the pulp in company with the bloodvessels and pass occlu- 
sally through the central portion of the tissue. These bundles branch 
and anastomose with each other very freely. Most of the fibers lose their 
medullary sheath before reaching the layer of Weil, in which position 
they form a plexus of non-medullated fibers; from these fibers free endings 
are given off, which penetrate between the odontoblasts. In some cases 
these have been followed over on to the dentinal ends of the odontoblasts, 
but in no instance have they been followed into the dentinal tubules. 

The Functions of the Pulp. — The pulp performs two functions, a vital 
and a sensory. 

The vital function is the formation of dentin, and is performed by 
the layer of odontoblasts. This is the principal function of the pulp, 
and it is first manifested in the development of the tooth before the 
dentinal papilla is converted into the dental pulp by being enclosed 
in the formed dentin. After the tooth is fully formed the vital func- 
tion is not manifested unless the pulp is stimulated by some excitation 
affecting trophic centres and which causes the formation of secondary 
dentin. There are some exceptions where the formation is entirely 
local. 

The Sensory Function. — In regard to sensation, the pulp resembles 
an internal organ. It has no sense of touch or localization, and responds 
to stimuli only by sensations of pain. The pain is usually localized 
correctly with reference to the median line, but, aside from that, is 



94 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



localized only as it is referred to some known lesion. If several pulps 
on the same side of the mouth and in teeth of both the upper and lower 
arches were exposed so that they could be irritated without impressions 
reaching the peridental membrane, and the patient were blindfolded, 
it would be impossible for him to tell which of the pulps was touched. 
The pain originating from a tooth pulp may be referred to the wrong 
tooth or to almost any point on the same side supplied by the fifth 
cranial nerve. 

The pulp is especially sensitive to changes of temperature, but is 
incapable of differentiating between heat and cold; this fact is often 
made use of in differential diagnoses. The pulp is also very sensitive 
to traumatic and chemical irritations, even when these are conveyed 
to it through the agency of the dentinal fibrils. Dr. Huber has suggested 1 
that this transmission may be accomplished by the traumatic or chemical 
action upon the fibrils setting up metabolic changes in the odontoblastic 
cells, which act as stimuli to the sensory nerves ending between the 
cells of that layer. 

CEMENTUM 

The cementum covers the surface of the dentin apically from the 
border of the enamel, lapping slightly over the enamel at the gingival 
margin (Fig. 69). It forms a layer, thickest in the apical region and 



Fig 




Gingival border of enamel, showing the cementum overlapping it: E, enamel; C, cementum; 

D, dentin. (About 40 X ) 



1 Dental Cosmos, October, 1898. 



CEMENTUM 



95 



between the roots of bicuspids and molars, and becoming thinner as the 
gingival line is approached. The cementum resembles subperiosteal 
bone in structure, but differs from it in the character and arrangement 
of the lacunae and in the absence of Haversian systems; the layers, or 
lamellae, of the cementum also are less uniform in character than those 
of bone. 

The function of the cementum is to furnish attachment for the 
fibers of the peridental membrane which holds the tooth in its position. 
The surrounding tissues are never in physiological connection with the 
outer surface of the dentin, except to form cementum over it or to 



Fig. 70 




Cementum near the apex of the root: Gt, granular layer of Tomes; L, lacunae, b, point at which 
fibers were cut off and reattached. (About 54 X ) 



remove its substance by absorption; and when absorption of the dentin 
has occurred on the surface of a root it is never repaired except by the 
formation of cementum to fill up the cavity and reattach the membrane. 
The cementum is intermittently formed during the functioning of 
the tooth, being added layer after layer over the entire surface of the 
root, the difference in thickness of the tissue in the gingival and apical 
portions being chiefly, though not entirely, due to the difference in 
thickness of each layer in the two positions (Figs. 69, 70). The cemen- 
tum on the roots of newly erupted teeth is thin, and on the roots of 
teeth of old persons is thick, This continued formation of cementum 



90 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

Fig. 71 




Thick lamellae of cementum with many lacunae, filling an absorption in dentin: L, lacunae; H, 
Howship's lacunae filled; D, dentin. (About 250 X.) 



Fig. 72 




Two 



fields of cementum showing penetrating fibers: Gt, granular layer of Tomes; C, cementum 
not showing fibers ; F, penetrating fibers. (About 54 X.) 



PERIDENTAL MEMBRANE 97 

is due to the necessity for change and reattachment of the fibers of the 
membrane. 

In the gingival portions, where the cementum is thin, the tissue is 
clear and apparently structureless, and usually contains no lacuna?; 
while in the apical half and between the roots the lacunae are numerous. 
In general, wherever the lamellae are thin, the lacunae are absent; but 
where the lamellae are thick they are found. The canaliculi which 
radiate from the lacunae are not as regular as in the case of the lacunae 
of bone. Sometimes they are numerous, sometimes few; they may 
extend from a lacuna in all directions, or they may be confined to one 
side, usually the side toward the surface of the cementum (Fig. 71). 

The cementum is penetrated through all its layers by fibers of the 
peridental membrane which have been embedded in the matrix of the 
tissue and calcified along with it. The first layer — that is, the one next 
to the dentin — is usually structureless and shows no fibers in it, at 
least in its inner half. In ground sections the embedded fibers often 
appear in a number of layers, while they are not apparent in the rest 
of the thickness. This is because just before and just after the forma- 
tion of the layers in which they appear the fibers were cut off and 
reattached, changing their direction, so that in the other layers the 
fibers are cut transversely or obliquely. This is illustrated in Fig. 72. 
These embedded fibers are very numerous in some places. If properly 
stained, the tissue seems almost a solid mass of fibers. In ground 
sections these have sometimes been mistaken for minute canals from the 
fact that they are not always as fully calcified as the cementum matrix, 
and shrinkage causes the appearance of little open canals. 

Hypertrophies of the cementum (formerly often called exostoses, or 
excementoses) are very common. The increased thickness may be of 
one lamella or of several lamellae in the region of the hypertrophy, or 
all of the layers from first to last may take part in it. Small local thick- 
enings of a single lamella are seen in connection with the peridental 
membrane wherever a specially strong bundle of fibers is to be attached 
to the root to support the tooth against some special strain. 

PERIDENTAL MEMBRANE 

The peridental membrane may be defined as the tissue which fills 
the space between the root of the tooth and the bony wall of its alveolus, 
surrounds the root occlusally from the border of the alveolus, and 
supports the gingiva. It has been referred to under many names, 
as pericementum, dental periosteum, alveolodental periosteum, etc. 
While this tissue performs the functions of a periosteum for the bone 
of the alveolus, it differs in structure from the periosteum in any posi- 
tion, so that any name including the word periosteum or implying a 
double membrane should be avoided. 
7 



98 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



The peridental membrane belongs to the class of fibrous membranes, 
and is made up of the following structural elements: 



G \ 



Al < 



Fig. 




Ap 1 



Diagram t»f the fibers of the peridental membrane: G, gingival portion; Al, alveolar portion; 
Ap, apical portion. (From a photograph of a section from incisor of sheep.) 



1. Fibers. 2. Fibroblasts. 3. Cementoblasts. 4. Osteoblasts. 5 
Osteoclasts. 6. Epithelial structures which have been called the glands 
of the peridental membrane. 7. Bloodvessels. 8. Nerves. 

The peridental membrane performs three functions — a physical 



PERIDENTAL MEMBRANE 



99 



function, maintaining the tooth in relation to the adjacent hard and 
soft tissues; a vital function, the formation of bone on the alveolar 



Fig. 74 




Longitudinal section of peridental membrane from young sheep, showing fibers penetrating 
cementum: D, dentin; C, cementum, showing embedded fibers; F, fibers running to outer layer 
of periosteum covering the alveolar process; F* , fibers running to the bone at the border of the 
process; B, bone. (About 80 X) 



wall and of cementum on the surface of the root; and a sensory function, 
the sense of touch for the tooth beihg- exclusively in this membrane. 



100 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

The fibrous tissue of the membrane is of the white variety, and may 
be divided into two classes, the principal fibers and the indifferent or 
interfibrous tissue. The principal fibers may be defined as those which 
spring from the cementum and are attached at their other end to the 
bone of the alveolar wall, to the outer layer of the periosteum covering 
the surface of the alveolar process, to the cementum of the approximating 
tooth, or become blended with the fibrous mat of the gum supporting 
the epithelium. They were so called by Dr. Black, not only because 
they form the principal bulk of the tissue, but they also perform the 
principal function of the membrane, the support of the tooth and sur- 



Fig. 75 




Longitudinal section of the peridental membrane in the gingival portion: D, dentin; iV.Nasmyth's 
membrane; C, cementum; F, fibers supporting the gingivus; F 1 , fibers attached to the outer layer of 
the periosteum over the alveolar process; F 2 , fibers attached to the bone at the rim of the alveolus; 
B, bone. (About 30 X) 



rounding tissues. The interfibrous tissue, also of the white variety, but 
made up of smaller and more delicate fibers, is found filling spaces 
between the principal fibers and surrounding and accompanying the 
bloodvessels and nerves. 

For convenience of description and study, the peridental membrane 
is divided into three portions : the gingival, that portion which surrounds 
the root occlusally from the border of the alveolar process; the alveolar, 
the portion from the border of the process to the apex of the root; and 
the apical portion, surrounding the apex of the root and filling the 
apical region (Fig. 73). 



PERIDENTAL MEMBRANE 



101 



The principal fibers spring from the cementum, the cementoblasts 
building up the matrix around them and then calcifying both matrix 
and fibers, in this way implanting their ends into the surface of the 
root. In Fig. 74 the fibers are seen passing through the last-formed 
layer of cementum. In most positions the fibers as they spring from 
the cementum appear as well-marked bundles of fine fibers. A short 
distance from the surface of the root they break up into smaller bundles, 
which interlace and are reunited into larger bundles, to be attached 
at their other extremity to the bone, cementum, or fibrous tissue. 



Fig. 76 




Transverse section of the peridental membrane in the gingival portion (from sheep) : E, epithe- 
lium: F, fibrous tissue of gum; B, point where peridental membrane fibers are lost in fibrous mat 
of the gum; P, pulp; F , fibers extending from tooth to tooth. (About 30 X) 

To arrive at an understanding of the arrangement of the fibers of 
the peridental membrane, they must be studied in both longitudinal and 
transverse sections. In longitudinal sections of the membrane, in the 
gingival portion (Fig. 75), the fibers springing from the cementum at 
the gingival line pass out for a short distance at right angles to the 
long axis of the tooth and then bend sharply to the occlusal, 1 passing 



1 In describing the direction and inclination of peridental membrane fibers they are always 
traced from the cementum to the bone, the angle with the horizontal plane being formed at the 
surface of the cementum. 



102 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

into the gingiva to support it and hold it closely against the neck of 
the tooth. These fibers are most numerous on the lingual side, where 
food is brought against the gingiva with force in mastication and tends 
to crush it down. In the middle of the gingival portion the fibers pass 
out at right angles to the axis and are blended with the fibrous mat of 
the gum on the labial and lingual sides, or are attached to the cementum 
of the adjoining teeth on the approximal sides. A little farther from the 
gingival line the fibers are inclined slightly apically, passing over the 
border of the process to be attached to the outer layer of the periosteum. 
These fibers are especially large and strong. Just at the rim of the 
alveolus the fibers are inclined slightly apically and are inserted into 
the bone, forming the edge of the process. 





Fig. 77 




BBBMIHI 


Bl- 


^^^MB 




|9|BBH^^^^^@^^v-^| 




H^R^^^^^^^^^^BB H 




i^^^^^^^HH 




31 




'HHB 


B- 


', ^^SSSil^ 


Bl- 


>|P|||jM 




HHfe?'- II 



Fibers at the border of the alveolar process (from sheep) : D, dentin; C, cementum; F, fibers extend- 
ing from cementum to bone; Bl, bloodvessel; B, bone. (About 80 X) 



In transverse sections of the membrane in the gingival portion (Fig. 
76) the fibers spring from the cementum in large bundles; at the centre 
of the labial surface they extend directly outward, breaking up into 
smaller bundles, passing around bloodvessels and bundles of fibers, and 
blending with the fibrous tissue supporting the epithelium. Passing 
mesially and distally toward the corners of the root, the fibers swing 
around laterally and pass to the cementum of the next tooth. On the 
approximal sides the fibers suddenly divide into smaller bundles, which 
wind in and out around bloodvessels, and bundles of fibers which pass 
into the gingiva and are reunited into large bundles to be inserted into 
the cementum of the next tooth. On the lingual side the arrangement 
is like that of the labial, except that the distance to which the fibers of 



PERIDENTAL MEMBRANE 



103 



Fig. 78 




Transverse section of the peridental membrane in the occlusal third of the alveolar portion 
(from sheep) : M, muscle fibers ; Per, periosteum ; Al, bone of the alveolar process ; Pd, peri- 
dental membrane fibers ; P, pulp ; D, dentin ; Cm, cementum. 



104 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

the membrane can be followed before they are lost in the fibrous mat of 
the gum is usually greater than on the labial. 

In the occlusal third of the alveolar portion of the membrane the 
fibers pass, at right angles to the axis of the tooth, directly from the 
cementum to the bone. In this position the fibers are large and do not 
break up into smaller bundles, but the original fibers can be followed 
uninterruptedly from the cementum to the bone (Figs. 74 and 77). 
In the middle third the fibers are inclined occlusally, and this inclina- 
tion increases as the apical third is approached. In the apical third 
the inclination is greatest, and the fibers as they arise from the cemen- 
tum are very large and break up into fan-shaped fasciculi as they pass 
across to the bone. In the apical portion the fibers radiate from the 
apex in all directions across the apical region and spread out in fan- 
shaped bundles like those in the apical third of the alveolar portion. 

In a transverse section near the border of the alveolus (Fig. 78), at 
the centre of the labial surface of the root, the fibers are seen to extend 
directly out from the surface of the root to the bone of the process, 
excepting where they are diverted to pass around bloodvessels. Passing 
around distally at the corner of the root, the fibers swing laterally so as 
to be almost at a tangent to the surface of the root, and are inserted 
much farther to the distal on the wall of the alveolus. A similar arrange- 
ment is noticed at the other corners of the root, though these tangential 
fibers are usually more marked at the distal than at the mesial corners. 

Studying the arrangements of the fibers with reference to the physical 
function of the membrane, it is seen to be the best that could be devised 
to support the teeth against the force of mastication and to support 
the tissues about them. In the gingival portion the fibers passing 
from tooth to tooth form the foundation for the gingivae between the 
teeth filling the interproximal spaces; so that if these fibers are cut 
off from the cementum, by extending a crown band too far, or by the 
encroachment of calculary deposits beginning in the gingival space, 
the gingiva drops down and no longer fills the interproximal space. In 
the alveolar portion the fibers at the border of the process and those 
at the apex of the root together support the tooth against lateral strain, 
while those in the rest of the alveolar portion are so arranged as to 
swing the tooth in its socket and support it against the force of occlu- 
sion (Fig. 73). As seen from the transverse section, the fibers of the 
occlusal third of the alveolar portion are so arranged as to support 
the tooth against forces tending to rotate it in its socket. 

Cellular Elements of the Membrane. — The fibroblasts are spindle-shaped 
or stellate connective-tissue cells which are found between the fibers 
as they are arranged in bundles. In sections stained with hematoxylin 
they take the stain deeply, and the fibers, unstained, are differentiated 
by the cells lying in rows between them. The number of fibroblasts in 
the membrane decreases with age. They are large and numerous in the 



PERIDENTAL MEMBRANE 



105 



membrane of a newly erupted tooth, and comparative/ small and few 
in the membrane around an old tooth. This is characteristic of fibro- 
blasts in other positions. The fibroblasts are shown as they appear 
in a hematoxylin-stained section with low powers in Fig. 79, which 



Fig. 




Fibers and fibroblasts from transverse section of membrane: F, fibers cut transversely; F>, fibers 
cut longitudinally, showing fibroblasts. (About 80 X ) 

gives part of the membrane in the gingival portion between two teeth. 
The cells are seen as spindle-shaped dots which mark out the fibers; 
at F they are seen in a position where the fibers are cut transversely. 
With higher powers these cells appear as in Figs. 81 and 90. 



Fie. 80 



Cementoblasts. (Drawing by Dr. Black.) 

The cementoblasts are the cells which form the cementum, and are 
found everywhere covering the surface of the root between the fibers 
which are embedded in the tissue. While these cells perform the same 
function for the cementum as the osteoblasts do for bone, they are in 
form very different from the osteoblasts. The cementoblasts are always 
flattened cells, sometimes almost scale-like, and when seen from above 



106 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

are very irregular in outline. This irregularity of outline is caused by 
the cells fitting around the attached fibers of the membrane so as to 
cover the entire surface of the cementum between the fibers. Fig. 80, 
from a drawing by Dr. Black, 1 shows several cementoblasts as seen 
when isolated by teasing. The cementoblasts have a central mass of 
protoplasm containing an oval nucleus, and short irregular processes 
which fit around the fibers as these spring from the surface of the cemen- 
tum. Fig. 81 shows them in section perpendicularly to the surface 



Fig. 81 




Transverse section, showing the cellular elements: Fb, fibroblasts; Ec, epithelial structures; 
Cb, cementoblasts; Cm, cementum; D, dentin. (About 900 X) 

of the root, where they are crowded between the fibers. The cemento- 
blasts often have processes projecting into the cementum like those 
from the osteoblast, but processes projecting into the membrane have 
never been demonstrated. 

In the formation of the cementum occasionally a cementoblast be- 
comes enclosed in the formed tissue filling one of the lacunae, in which 
position it becomes a cement corpuscle. 



1 Periosteum and Peridental Membrane. 



PERIDENTAL MEMBRANE 



107 



Fig. 82 



HB 




PdB 



Border of growing- process : Cm, cementum : Pd, peridental membrane : Pd.B, solid subperidental 
and subperiosteal bone with imbedded fibers ; Ms, medullary space formed by absorption of 
the solid bone; H.B, Haversian-system bone without fibers; Per, periosteum. (About 50 X.) 



108 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 



The osteoblast* of the membrane cover the surface of the bone, forming 
the wall of the alveolus, lying between the fibers which are built into 
the bone. In form and function they are like the osteoblasts in attached 
portions of the periosteum. They form bone around the ends of the 
peridental-membrane fibers, building them into the substance of the 
bone. The bone thus formed over the wall of the alveolus is like the 



Fig. 83 



Pd M 



PdB 




HB 



Penetrating fibers in bone: PdM , peridental membrane; Ob 1 , osteoblasts of peridental membrane; 
Ob-, osteoblasts of medullary space; PdB, solid subperidental and subperiosteal bone with embedded 
fibers; Ms, medullary space formed by absorption of the solid subperidental bone with embedded 
fibers; HB, Haversian-system bone without fibers built around the medullary space. (About 
200 X) 



solid subperiosteal bone, and is penetrated throughout its thickness 
by the embedded fibers; but, as with the subperiosteal bone, it is con- 
stantly being penetrated by perforating canals, the solid bone being 
removed by resorption and rebuilt in bone with Haversian systems. 
This process is shown in Fig. 82, a section through a growing portion 



PERIDENTAL MEMBRANE 
Fig. 84 



109 




Osteoclast absorption of bone over permanent tooth : Oc, osteoclasts ; B, bone of crypt wall 
F, fibrous tissue of follicle wall ; A, ailieloblasts. (About 62 X ) 

Fro. 85 




Osteoclasts: Oc, osteoclasts : B, bone. (About 66 X) 



110 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

of the process around a permanent tooth. A higher power (Fig. 83) 
shows the penetrating fibers and the formation of Haversian-system 
bone without fibers, in the body of the process. 

The osteoclasts, or myeloplaques, are bone-destroying cells (Fig. 
84); they act not only upon bone, but also upon cementum and dentin. 
They are oval cells, often as much as 30 microns in diameter, and con- 
tain many nuclei — from two or three to fifteen or twenty. They are 
often called giant cells. The osteoclasts are not constantly found in the 
membrane, but make their appearance whenever calcified tissues are to 
be destroyed. In order for them to act upon the tissue they must lie 
in contact with its surface, and therefore the first step in absorption of 
the peridental membrane is the cutting off of the fibers embedded in 
the bone or cementum. Where the osteoclasts act upon the surface of 



Fig. 86 




Record in the calcified tissue of an absorption repaired: D, dentin; Cm, cementum filling 
absorption cavity. (About 40 X ) 



the tissue they produce bay-like excavations, in which they lie, and 
which are known as Howship's lacunae. These excavations are shown 
in Fig. 87, though the osteoclasts have disappeared. In Fig. 86, from 
a ground section, the basin-like excavations are shown filled with new- 
formed cementum, thus leaving in the tissue the record of an absorp- 
tion repaired. In absorption of the roots of the temporary teeth the 
osteoclasts are found not only in the membrane and attacking the 
surface of the root, but all through the medullary spaces in the bone, 
removing the temporary alveolar process. 

When absorption is going on at one place on the surface of a 
root a compensating formation of cementum is going on at another, 
so that not all of the fibers of the membrane are cut off. This is 
illustrated by sections of temporary teeth that are ready to be shed 
(Fig. 87). 



PERIDENTAL MEMBRANE 



111 



Epithelial Structures of the Membrane. — The peridental membrane 
contains cellular structures of epithelial character which are so con- 



Fig. 87 




Root of a temporary incisor, showing absorption and rebuilding of cementum (from sheep): 
G gingiva; D, dentin; Cm, cementum; Ab, absorption cavity, showing Howship's lacunae; Cm 1 , 
new-formed cementum. (About 50 X ) 



spicuous that they demand consideration, though their nature and 
origin are not as yet fully understood. 

These structures were first well illustrated and described by Dr. 
Black, in his work on the periosteum and peridental membrane, in 1887, 



112 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

Fig. 88 




Diagram of glands of peridental membrane. (G. V. Black.) 
Fig. 89 




Epithelial structures of the peridental membrane (from sheep) : Fb, fibroblasts ; Ec, epithelial 
structures; CO, cementoblasts ; Cm, cementum ; D, dentin. (About 468 X ) 



PERIDENTAL MEMBRANE 



113 



and were called by him the glands of the peridental membrane. About 
the same time von Brunn 1 described what are probably the same struc- 
tures, and which he regarded as embryonal remains of the inner layer 
of the enamel organ, which he described as growing down over the 
surface of the root. These structures appear as cords of epithelial cells 
arranged in the form of a network winding between the fibers of the 



Fig. 90 




Epithelial structures (from sheep): Fb, fibroblasts; Ec, epithelial structures; Cb, cementoblasts; 
Cm, cementum; D, dentine. (About 700 X) 

membrane, very close to the cementum and surrounding the root almost 
to the apex. Their arrangement is illustrated in Fig. 88, a diagram by 
Dr. Black. The meshes of the net are close in the gingival portion of the 
membrane, but grow more and more open in the alveolar portion. They 
are not confined to the membranes of young teeth or the temporary 
dentition, as Dr. Black has shown them in the membrane of a tooth from 
a man, seventy years old, though, like all of the cellular elements of the 
membrane, they become less numerous as age advances. These struc- 



Archiv f. mikros. Anat., 1887. 



114 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

tures are specially well shown in the membranes of the pig and sheep. 
Fig. 89 shows their appearance in a transverse section of the root of an 
incisor of a sheep; here they swing out from the surface of the cemen- 
tum and back again in loops, winding in and out among the fibers. 
Studied with higher powers (Fig. 90), they are seen to be made up of 
epithelial cells with large oval nuclei which react to the characteristic 
epithelial stains. They are arranged in cords, though sometimes what 
seems to be a lumen of a gland tubule can be found (Fig. 91). The 



Fig. 91 






Epithelial structures: Ec, epithelial cord, apparently showing a lumen; Cb, cementoblasts; 
Cm, cementum; D, dentin. (About 500 X) 



cords are invested with a delicate basement membrane, but no special 
relation to bloodvessels has been demonstrated. The attempt to show 
their connection with the surface epithelium has thus far failed. As the 
gingiva is approached (Fig. 92), they seem to swing out from the sur- 
face of the root and are lost between the projections of the epithelium 
lining the gingival space. There is evidence that these structures are, 
at least in some cases, of importance as the primary seat of pathological 
conditions of the membrane. 



PERIDENTAL MEMBRANE 
Fig. 92 



115 




Longitudinal section: Ep, epithelium lining the gingival space; Gg, gingival gland, so called, 
X>, dentin ; N, Nasmyth's membrane ; Du, duct-like structure stretching away toward the gin- 
giva from the epithelial cord, seen at Ec ; Cm, cementum, separated from the dentin by 
decalcification. (About 50 X ) 



110 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 

Fig. 93. 




Fig. 94. 




Young and old membranes (from sheep) : D, dentin: Cm, cementum ; Cni 1 , thickening of cemen- 
tum to attach fibers at the corner; Pd, peridental membrane ; B, bone forming the wall of the 
alveolus ; P, pulp. (About 80 X ) 



PERIDENTAL MEMBRANE 117 

Bloodvessels and Nerves of the Membrane. — Bloodvessels. — The blood 
supply of the peridental membrane is very abundant. Several vessels 
enter the membrane from the bone in the apical region. These arteries 
branch and divide, forming a rich network, from which the capillary ves- 
sels are given off. The arterial network is constantly receiving vessels 
which enter the membrane through Haversian canals opening on the wall 
of the alveolus, and in this way the size of the vessels passing occlusally 
is maintained. Arterial vessels also enter the membrane over the border 
of the process. This double or triple supply of the membrane is impor- 
tant, as it maintains the health of the membrane when the supply entering 
through the apical region is entirely cut off by alveolar abscess. While 
the arterial supply of the membrane is very rich, the capillaries in the 
membrane are comparatively few. This is, however, a characteristic 
of connective-tissue membranes. 

The nerves of the peridental membrane have not been sufficiently 
studied to be described in detail. Six to eight medullated nerve trunks 
enter the apical region in company with the bloodvessels, and they 
receive other trunks through the wall of the alveolus and over the border 
of the process, but the manner of their .distribution and the nature of 
their endings are not known. 

The Changes which Occur in the Membrane v/ith Age. — When a tooth 
is erupted the roof of the bony crypt in which it was enclosed in the 
body of the bone is removed by absorption and the crown advances 
through the opening. The diameter of the alveolus at that time is, 
therefore, greater than the greatest diameter of the crown, and the 
peridental membrane which fills the space is very thick. By the forma- 
tion of bone on the wall of the alveolus and the formation of cementum 
on the surface of the root, the thickness of the membrane is reduced. 
In the young membrane most of the large bloodvessels are found in 
its outer half, forming a rather defined vascular layer near its centre. 
In the old membrane most of the bloodvessels are found very close to 
the surface of the bone, often lying in grooves in its surface. Both 
young and old membranes are illustrated in Figs. 93 and 94, which are 
taken from the temporary teeth of a sheep, one just after eruption and 
the other shortly before the time of shedding. 



CHAPTEE III 
ANTISEPSIS IN DENTISTRY 

By JAMES TRUMAN, D.D.S., LL.D. 

Antisepsis has now become recognized as of vital importance in all 
operations connected with the human organism. The oral cavity, 
with its contents, has been considered, of recent years, one of the most 
important factors in producing disease, and hence both dental and 
medical practitioners have realized that hygienic and prophylactic 
measures must begin with this, the vestibule of the entire system. It 
is here that the pathogenic organisms find a prolific culture field and 
with the possible result of equally infecting many important organs. 
That this was not, in earlier dental practice, fully recognized is due to 
the fact that the part played by bacteria was not known thirty years 
ago, as it is now, hence cleanliness, as then understood, was held to be 
sufficient. This, however, will not meet the requirements of the 
present, and the dental practitioner neglecting to avail himself of all 
means and appliances necessary to affect antisepsis is assuming a grave 
responsibility. The skepticism which formerly prevailed as to the value 
of antiseptic measures had its origin in the prevailing idea that the oral 
fluids were, with ordinary cleanliness, sufficient to prevent infection. 

This has never been proved through laboratory experiments, but clini- 
cal observation and long experience have demonstrated that injuries in 
the mouth ordinarily heal rapidly. It seems unreasonable to suppose that 
a fluid peculiarly subject to fermentation should have this effect, and this 
has led some to ascribe it to a vital influence. Miller 1 says of this : " It 
is a very fortunate provision that the gums in a healthy state offer so 
powerful a resistance to the invasion of the germs of most infectious dis- 
eases. For this reason a wound in the gums may be followed by scarcely 
any reaction whatever, while a similar wound on the hand with the same 
instrument may produce most disastrous results. It has been attempted 
to account for this fact on the supposition that the saliva has an anti- 
septic action, in evidence of which we are often reminded that dogs lick 
their wounds, and that these heal rapidly. . . I doubt if there is 
anyone who would wish us to believe that the dead saliva has even the 
slightest antiseptic properties, in consideration of the fact that saliva, 

i Dental Cosmos, July, 1891. 
(118) 



ANTISEPSIS IX DENTISTRY 119 

especially when it contains much organic matter, readily putrefies. If 
the saliva possesses any such property, it must be sought for in its living 
histological elements — i. e., in the living leukocvtes or phagocvtes." 1 

While it is true that there exists a degree of exemption from serious 
results, leading to indifference and careless management of cases, it is 
equally true that infection has resulted in the experience of almost 
every operator in dentistry. 

Prior to the period when Lister announced that all operations in 
surgery should be performed antiseptically, and made modern surgery 
possible, this ignorance was excusable; but at the present time, with the 
accumulated knowledge in bacteriology, it should be impossible for any 
dental operator to neglect the procedures under this head considered 
absolutely essential for the general surgeon. 

The difficulties attending antisepsis in dentistry far exceed those in 
other branches of surgery. The dentist is necessarily obliged to meet 
conditions hourly that seem to preclude absolute freedom from sources 
of contamination. If he were to take the same precautionary measures 
now regarded as necessary for the surgeon, he would find practice almost 
impossible. AYhile this is true, it does not follow that every effort 
should not be made to approach absolute surgical cleanliness. 

The usual methods employed to accomplish this, while valuable to 
a limited extent, are by no means equal to what could readily be secured 
without consuming much time or patience. The dentist is usually sat- 
isfied that he has fulfilled all antiseptic precautions when he has dipped 
his instrument in some antiseptic fluid, generally carbolic acid. Little 
or no attention is paid to the possibility of infection from the rubber 
dam, towels, hands, and the variety of instruments that enter into dental 
operations. Some of the latter, as, for instance, the separator, are more 
liable to carry infection than the excavator, the one generally regarded 
as most important. 

The appliances ordinarily in daily use are the rubber dam, excava- 
tors, broaches, pluggers, clamps, ligatures, separators, drills, hand- 
pieces, napkins, and forceps. It is safe to assume that but few of these 
will receive any attention beyond ordinary washing. The rubber-dam 
is too often used as it is furnished by the manufacturer. If an attempt 
at cleanliness is made, it consists in washing the dam in cold or warm 
water, this being regarded as sufficient. 

The boiling of the rubber in water has the effect of reducing the 
absolute tenacity of the material. The continuation of the boiling 
for fifteen minutes, while it does not seem to affect immediately the 
elasticity, renders the rubber apt to tear, a very objectionable feature. 
If kept for a few days it deteriorates rapidly. The writer has tested 

1 For an elaborate study of this problem see Experimental Study of the Different Modes of 
Protection of the Oral Cavity against Pathogenic Bacteria, by Arthur C. Hugenschmidt, M.D., 
Dental Cosmos, xxxviii, p. 797. 



120 ANTISEPSIS IN DENTISTRY 

this at various periods of boiling without any marked difference in 
results. The boiling of rubber cannot, therefore, be recommended. 
This is to be regretted, for it is evident that the rubber, as it comes 
to the dentist in sheets, is a very unsafe material to place in the mouth. 
To meet this objection there remains but one remedy, and that is thor- 
ough washing in water with a good antiseptic soap. This has no injurious 
effect on the material, but while this is true, it cannot be regarded a? 
effective sterilization, but with other aids may answer the purpose. 

The dam should never be applied without first bathing the gingivae 
of the teeth to be covered by the rubber with a good antiseptic wash. 
The most effectual is, probably, a 1 per cent, alcoholic solution of 
hydronaphthol. Upon the removal of the dam this bathing should 
be repeated, saturating thoroughly the free margin of the gums. This 
is especially required after the use of ligatures and clamps. 

It is needless to add that the rubber should never be used a second 
time on a different patient. 

When it is remembered that this is passed between teeth and usually 
forced up under gingival margins with ligatures, or clamps, frequently 
lacerating the surface, it becomes evident that the possibility of infection 
is always present. If infection does not occur from the rubber, it is 
almost certain to produce a wound in a locality extremely favorable for 
the growth of pathogenic germs. The result is innumerable lesions 
that may extend to pericemental inflammations. The great increase 
in the past twenty-five years of gingival inflammations subsequent to 
operations in mouths of more than ordinary health must be partly 
ascribed to this cause. 

Excavators ordinarily receive the most attention, and yet, when their 
use is considered, they possibly require the least. It is rarely necessary 
to use the excavator outside of a cavity, where infection, if at all pos- 
sible, would do the least harm, for the continual washing of the cavity, 
as the operator proceeds, reduces the danger to a minimum. Broaches 
and all instruments intended to enter the pulp canals, require the most 
careful attention, and this applies with equal force to drills; yet it is 
feared that both of these, loaded though they are with septic matter, 
receive but indifferent care. When the dangerous possibilities which 
may result from this negligence are considered, it becomes a serious, if 
not a criminal offence. The difficulty in making these instruments germ- 
free and in keeping them from becoming contaminated is fully appre- 
ciated; yet the effort must be made, and it is not a difficult procedure, 
nor does it require a large consumption of time — an important item to 
the dental operator. 

Pluggers cannot be regarded as a source of infection. They are 
used solely in connection with metal, and therefore strict cleanliness 
is all that is absolutely required. It is fortunate that this is so, for 
these instruments require unusual care to protect them from rust. 



ANTISEPSIS IN DENTISTRY 121 

Hence immersion in an antiseptic fluid may be deleterious and not 
required. 

Separators — and under this head are included metal ones with screw 
attachments and wedges — require special attention, but probably receive 
the least. They should be made as nearly sterile as possible before 
their use upon a patient. 

Hand-pieces, of the various kinds in use, are probably the most 
difficult to keep thoroughly clean. While they do not come in direct 
contact with the tissues of the mouth, they may indirectly, by contam- 
inating the hands, produce unpleasant results. Frequent taking apart 
and boiling are essential, and should not be omitted. 

Napkins from the ordinary wash have been and are used with con- 
fidence that no bad results from use can follow. If the laundry is con- 
fined to the home, this may ordinarily be true, but the indiscriminate 
mingling of washes indulged in by the commercial laundryman is 
always a menace to health, Where napkins of the latter character are 
to be used they should be subjected to the sterilizing process. 

The chair occupied by a variety of patients may be a source of dis- 
ease, and should be carefully cleansed, especial care being taken with 
the head-piece. The latter should be covered with a clean napkin, to 
be changed for every patient. 

The cuspidor, where the fountain is not used, is ordinarily an abom- 
ination, for here, if anywhere, will carelessness be manifest. There can 
be no excuse for this, as thorough daily scalding with boiling water and 
the use of antiseptics will keep it measurably free from unpleasant 
consequences. 

Glasses require to be thoroughly boiled both before and after use. 
Boiling should never be neglected with ejector tubes, either metal 
or glass, glass being generally used. Hard boiling in water for twenty 
minutes should be sufficient. 

The lancet is an instrument demanding especial care, as it may become 
a dangerous source of infection. 

This instrument should be thoroughly sterilized by boiling in water 
in which sodium bicarbonate has been added. This must never be 
neglected, mere dipping in carbolic acid, or a milder antiseptic, has 
very little value. 

The fact that the lancet must frequently be employed on infants 
during the eruptive stage of the deciduous teeth, demands special care, 
and before attempting its use the gums should be thoroughly washed 
with an antiseptic of a non-escharotic character. The difficulty attend- 
ant on lancing these teeth in private families, where this is generally 
required, can be in a measure overcome by the preparatory boiling 
process in the office and careful wrapping the blade in antiseptic cotton, 
and, before its final use, dipping it in an antiseptic solution, 1 per 
cent, solution of formalin preferred. 



122 



ANTISEPSIS IN DENTISTRY 



Fig. 95 



The forceps employed in extraction should be so constructed as to 
render the blades readily separable at the joint, and they should be 

boiled in soda bicarbonate solution for an 
hour. The recorded cases of infection 
from these instruments render this care 
imperative in all instances. 

Fig. 95 shows a convenient form of 
apparatus for sterilizing ordinary dental 
instruments by a boiling soda solution. 

The writer has found that a half to a 
teaspoonful of sodium bicarbonate to a 
pint of water, and kept at boiling temper- 
ature for fifteen minutes, is amply suffi- 
cient for sterilization and with no injury 
to instruments. The amount of sodium 
bicarbonate to be used will depend on the 
character of the water in a given locality. 
Abbott 1 in his valuable chapter on steri- 
lization, thus briefly describes those agents 
which will "prove of value in rendering 
infectious materials harmless; they are: 
Heat, either by burning, by steaming for 
from half an hour to an hour, or by 
boiling in a 2 per cent, sodium carbonate 
solution for fifteen minutes; 3 to 4 per cent, solution of commercial 
carbolic acid; milk of lime and a solution of chlorinated lime con- 
taining not less than 0.25 per cent, of perchlorine." It must be evident 
that the only available method, in this list, for the dentist is by boil- 
ing in sodium carbonate solution. 




Downie steam sterilizer. 






ORAL DISEASES AND THEIR TRANSMISSION 

The possibility of carrying disease from one person to another seems so 
self-evident that it ought not to require more than a word of caution, 
and yet it is clear that the attention given to this source of danger is by 
no means commensurate with the risks assumed constantly in practice. 
The peculiarly transitory character of much of dental practice precludes 
the possibility of any previous history of patients, and therefore every 
one should be regarded as a possible source of infection. 

Diseases the result of pathogenic bacteria independent of possible 
external infection are now in the main well understood, but by no means 
equally appreciated by medical practitioners, nor are they properly con- 
sidered by dental operators. Miller 2 states that "many facts favor the 



The Principles of Bacteriology, 1902. 

The Microorganisms of the Human Mouth, page 275. 



ORAL DISEASES AND THEIR TRANSMISSION 123 

supposition that a considerable number of pathogenic microorganisms 
may thrive in the juices of the mouth without showing in their vital 
manifestations any distinction from the common parasites of the oral 
cavity as long as the mucous membrane remains intact. If, however, 
the soft tissues have been wounded, as in extraction, or if the resistance 
of the mucous membrane has been impaired, these organisms may gain 
a point of entrance and thus become able to manifest their special 
actions." This fact, now well recognized, is being constantly demon- 
strated in the use of the various appliances that may, through careless 
handling, injure the mucous membrane. So much is this the case that 
a large proportion of gingival inflammations have undoubtedly had 
their origin from this cause. It has come under the observation of the 
writer that injuries thus received, although apparently unnoticed by 
dentist or patient, have resulted in the course of forty-eight hours in 
very disturbing pericementitis, confusing to the operator and very painful 
to the patient. The necessity for such antiseptic precautions here as are 
taken in general surgery is almost entirely overlooked. Before placing 
the coffer-dam, the clamp, or ligature, that portion of the mouth should 
be thoroughly washed with an antiseptic solution and an effort made 
to render the appliances equally sterile, or at least to inhibit develop- 
ment for a definite period. (See Treatment of Rubber Dam.) The 
evidence is abundant that many cases of pyorrhea alveolaris have 
had their origin from this careless indifference to accepted and necessary 
precautions. 

The mouth, as a source of disease to the general system, does not 
properly belong to this article to discuss, but its importance cannot be 
overlooked. Dental writers have devoted much attention to this sub- 
ject. It is for the dentist to understand that he is, to a large degree, 
responsible for the general health of his patient as far as the mouth is 
concerned, and he should insist on prophylactic measures that will at 
least reduce this source of disease to a minimum. The constant danger 
of what Miller aptly calls "auto-infection" from the collection and 
propagation of pathogenic bacteria in the fluids of the mouth should 
suggest to the dentist constant efforts to effect the removal of all deposits 
on the enamel, gingival margins, tongue, and mucous membrane. This 
line of study will bring about in the future an entirely different dentistry 
as to hygiene and prophylaxis from that practised at the present time. 

The pulp of a tooth is not ordinarily regarded as a point of infec- 
tion, and yet it is well known to be a serious menace to the health of 
an individual. Israel, quoted by Miller, 1 asserts that "the root canal 
furnishes a point of entrance even for the ray-fungus, actinomyces, 
and in one case the microscopic examination revealed the elements of 
this organism in the canal of a pulpless tooth." When it is considered 

1 The Microorganisms of the Human Mouth, p. 285. 



124 ANTISEPSIS IN DENTISTRY 

that some individuals have decomposed pulps in a number of teeth at 
the same time, and frequently a score of dead and broken roots, sending 
out their infectious material, it is not surprising that disease of a serious 
nature may supervene. While there is no record of cases coming within 
the observation of the writer of pulps producing pyemia directly, it 
is a well-known fact, supported by a long list of recorded cases, that 
alveolar abscess, with its concentration of putrid material, is liable 
to be followed by blood poisoning. 

There is no question that diseases of the digestive organs, of the 
lungs — in fact, of all the organs of the body — may be produced by 
infected material germinated in the mouth, and, indeed, through sputum 
ejected, may affect individuals remotely situated. 

Miller, 1 in considering this portion of the subject, says: "We know 
that under certain circumstances saccharomycetes may directly colonize 
in the mucous membrane of the mouth, and that in the mouths of 
enfeebled individuals bacteria may occasionally obtain a foothold. 
The mucous membrane of the mouth and pharynx is especially sus- 
ceptible to the action of certain germs of infection (those of diphtheria, 
syphilis, etc.), and large portions of the mucous membrane and the 
submucous tissue may be wholly destroyed by parasitic influences." 

The extended use of fixed dentures in the mouths of patients, of 
so-called bridge-work, and crowns of varied character, are prolific 
in mouth disorders. The removable bridge-piece, in a measure, over- 
comes liability to infection, provided the patient is properly instructed 
in its use and care, but the average patient has no real conception of 
the danger from infection from this source. It becomes the duty of 
every dentist, upon inserting such a piece, to insist on careful anti- 
septic methods of cleanliness. 

There is a phase of this subject that requires more extended inves- 
tigation. Inflammations of the mouth are not infrequent where great 
swelling is present. This may be observed around the lower third 
molars with no explainable cause in dead pulps, overlapping mucous 
membrane, retarded eruption, or malpresentation. It is evidently 
produced by bacterial invasion, but has not always yielded to anti- 
septic measures, and at times has resulted in abscess entirely independent 
of pulp devitalization. 

Crowns improperly placed are a continued source of disease, result- 
ing not only in the loss of the roots upon which these are placed, but 
in gingival and peridental inflammations, involving not only local 
pathological conditions, but extensive gastric disturbance. 

A recent report of three cases by Dr. John A. MeClain 2 in the medical 
practice of Dr. M. G. Tull is interesting as indicating possibilities. 
The first case was an extensive swelling posterior to the lower third 

1 The Microorganisms of the Human Mouth, p, 295. 

2 International Dental Journal, October, 1900. 



— 



INFECTION FROM MOUTH TO MOUTH 125 

molar. He could not connect it with that tooth, and suspected auto- 
infection. He had cultures made with negative results. His theory 
was that it was diphtheritic; and, although laboratory evidence was 
wanting, he determined to inject antitoxin. This injection was fol- 
lowed in twenty-four hours by an entire reduction of the swelling. 
All other efforts had previously failed to effect any result. Two other 
similar cases yielded to the antitoxin treatment in the same speedy 
manner. If this can be regarded as something more than a coincidence 
in practice, it may lead to an explanation of many similar anomalous 
pathological cases arising posterior to the third inferior molar, yet 
apparently not connected with it. Similar conditions have been the 
cause of much uncertain diagnosis and still more empirical treatment. 

The more the writer has considered this subject the more important 
it has, appeared; and he is convinced that, when the proper prophy- 
lactic measures come into use for the prevention of tuberculosis, in all its 
protean forms, antisepsis of the mouth will be given primary importance. 

The fact is very apparent that very little attention is given to anti- 
sepsis of the mouth in hospital treatment, and what is equally remark- 
able, our health authorities, in all cities in this country, have not until 
recently awakened to its importance in connection with the public 
schools. The authorities are usually quite sufficiently active as to 
the general health of the children, but pay not the slightest attention 
to the condition of the mouths and necessary dental care. When this 
care is given one of the open doors to tuberculosis will be closed. 



INFECTION FROM MOUTH TO MOUTH 

Infection from mouth to mouth through instruments is a difficult 
matter to prove by cases, but theoretically there can be no cause for 
disputation. The question will always arise, Was the lesion occasioned 
by auto-infection or by transmission ? The answer can rarely be given 
with the assurance desirable. In one instance, at least, in the writer's 
experience the origin was clearly traceable. This was in a patient of the 
better class, presenting for treatment in the clinic of the Dental Depart- 
ment of the University of Pennsylvania. Her teeth were remarkable for 
structure, regularity, and cleanliness; gums perfectly healthy. Necrosis 
of the anterior alveolar plate was threatened when first seen, and finally 
resulted in the entire destruction of the alveolar border and all the 
anterior upper teeth, but did not involve the maxilla. The history 
of the case as given was that a bicuspid had been extracted from the 
right superior region by a dentist notorious for his uncleanly habits. 
Not long thereafter the patient noticed a serious inflammation. These 
symptoms indicated a syphilitic infection, and the family physician was 
consulted, who insisted that no history of this disease existed and that 






126 ANTISEPSIS IN DENTISTRY 

infection must be the cause. The patient, through his treatment and 
that given locally, recovered, but was forced to wear an artificial sub- 
stitute. 

Cases of infection through extraction, either by the forceps or after- 
infection from the mouth, might be quoted almost indefinitely. Miller 
reports case upon case — in fact, the accumulation of these has become 
of serious moment; and yet, in the face of undisputed facts, dentists 
will continue to extract teeth frequently without any precautions, or, 
at most, relying on simple washing of the instrument. Some German 
writers contend that antisepsis after extraction is wholly unnecessary, 
as the clot formed is a sufficient protection. This is certainly not true 
in all cases. It is not always the fact that a clot is formed, or when 
formed that it serves an antiseptic purpose. One of the most serious 
cases that has fallen to the writer to treat was that of necrosis of the 
superior maxilla involving destruction of the right side, taking in all 
the teeth from the third molar to the lateral, the floor of the antrum, 
a portion of the nasal bones, and half of the hard palate. This was the 
result of the extraction of the third molar by a specialist before the 
days of antisepsis; whether it was the result of infection is difficult 
to determine. In the opinion of the writer, no extraction should be 
attempted until the instruments used have been thoroughly sterilized by 
boiling. Before the forceps are applied the parts surrounding the tooth 
should be well washed with an antiseptic solution. After the extraction 
the socket should be syringed with sterilized water, followed by some 
powerful disinfectant. In view of the serious results probable in this 
operation there is no longer any excuse for injuries resulting from 
infection, and a suit for malpractice could be well sustained against an 
individual who had failed to observe the well-understood methods of 
antisepsis, while no intelligent practitioner could conscientiously appear 
on behalf of the defendant. 



EXTERNAL INFECTION 

The danger to the operator from external infection from instruments 
is a constant menace; the constant use of these with general freedom 
from serious results, however, leads to a degree of carelessness not war- 
ranted by the ever-present danger from wounds. There is more real 
danger to the operator from this source than to the patient. All the 
excavators, drills, and broaches are hourly in contact with infectious 
matter, and it requires but a slight wound to produce any of the possi- 
bilities of blood poisoning. The operator should be on constant guard 
in this respect, upon the slightest abrasion immediately taking measures, 
to destroy all possibility of infection from germs that may have been 
introduced into the wound. This should at once be carefully washed 



IMPLANTATION AND TRANSPLANTATION 127 

and an escharotic employed, burning the parts. For this purpose zinc 
chlorid or carbolic acid are probably the best agents to use, followed by 
an antiseptic. The latter should be frequently renewed. Experience 
has demonstrated the value of turpentine in the various mechanical 
shops where this agent has been for many years in common use for 
wounds from rusted iron, the possibility of trismus resulting from such 
injuries being well understood. The writer has used this agent, after 
burning the wound, almost to the exclusion of other antiseptics. 

An illustration of the ever-present danger from wounds occurred 
to a friend of the writer's, one of the many young women who have 
graduated in dentistry in this country. She accidentally wounded her 
hand by a drill, and regarded it as of no moment. The result was severe 
blood poisoning that for two years kept her hovering between life and 
death. After suffering from severe metastatic abscesses, she was finally 
restored to partial health, but with her constitution shattered and her 
practice ruined for the time being. 



IMPLANTATION AND TRANSPLANTATION 

Previous to the recognition of the importance of antisepsis, the den- 
tists of that period had a very natural objection to reimplanting teeth; 
the practice of transplantation was then practically an unknown oper- 
ation. The danger of the operation was appreciated, but the reason 
was not then comprehended. When the study of bacteriology had 
advanced to a science through the labors of Pasteur, Koch, and a host of 
investigators, the reasons for this fear were explained, and the con- 
ditions necessary to avoid unpleasant results being understood, the 
danger from infection was changed to absolute security. It is, moreover, 
to be ever borne in mind that but for this knowledge implantation and 
transplantation could today not be practised without the probability of 
serious results. 

A case illustrating this point occurred prior to the knowledge of anti- 
sepsis in the hands of a well-known dentist. He had removed three 
teeth and successfully reimplanted them for the cure of a violent case of 
neuralgia presumably due to calcific depositions in the pulp and about 
the external portions of the roots. Relief was so immediate that upon 
return of the pain another tooth was attempted. Trismus followed, 
resulting in the death of the patient. It is safe to assume that this 
unfortunate result could not have happened under the antiseptic care 
usual at the present time, even imperfect as it frequently is. 

To accomplish antisepsis in this operation the greatest care is neces- 
sary. In transplantation, teeth being procured from other mouths, 
the danger is necessarily much increased. The method, adopted by 
some, of immersing these teeth in various antiseptic fluids cannot be 



128 ANTISEPSIS IN DENTISTRY 

commended. Miller 1 says of this; "It is generally accepted that the 
operator takes every possible precaution when he allows the tooth 
to lie for one-half to one hour in a 1 per cent, solution of carbolic acid, 
or in a 1 to 1000 solution of bichlorid of mercury. ... In order 
to reach bacteria that may have penetrated into the lacunae or chance 
vascular canals, a much longer action of the antiseptic is necessary, 
and to be perfectly certain that we have accomplished our object we 
should have recourse to boiling water." 

AGENTS USED FOR STERILIZATION 

The necessity for a definition of the words used in sterilization may 
not be apparent to the average reader, but, nevertheless, there seems 
to be a wide difference of opinion in the use of the terms germicide, 
disinfectant, and antiseptic. It is evident that these three cannot 
have a synonymous interpretation, but they are frequently used as 
meaning death to bacteria. Abbott 2 defines these terms as follows: 

" An antiseptic is a body which, by its presence, prevents the growth 
of bacteria without, of necessity, killing them; a body may be anti- 
septic without possessing disinfecting properties to any very high 
degree, but a disinfectant is always an antiseptic as well. 

"A germicide is a body possessing the property of killing bacteria." 

The possibility of injuring instruments has deterred dentists from 
using many of the agents recommended for the purpose of sterilization. 

Miller 3 made tests of various agents with indifferent results, with 
the exception of carbolic acid, trichlorphenol, and mercury bichlorid. 
The list tested included the following: 

Carbolic acid in 5 per cent, aqueous solution and in pure form. 

Lysol in 5 per cent, aqueous solution. 

Trichlorphenol in 5 per cent, aqueous solution. 

Sublimate in 5 per cent, aqueous solution; also in the strength of 
1 to 1000 of water. 

Benzoic acid in the strength of 1 to 300 of water. 

Potassium permanganate in 5 per cent, aqueous solution. 

Resorcin in 10 per cent, aqueous solution. 

Hydrogen peroxid in 10 per cent, aqueous solution. 

Saccharin in concentrated alcoholic and aqueous solution. 

/?-naphthol in 5 per cent, alcoholic solution. 

Pyoktanin in concentrated aqueous solution. 

Absolute alcohol. 

Antiseptin in 5 per cent, aqueous solution. 

Zinc sulfate in concentrated aqueous solution. 

The essential oils in 5 per cent, emulsions and in pure form. 

i Dental Cosmos, July, 1891. 2 The Principles of Bacteriology. 1909. 

3 Dental Cosmos, July, 1891, page 520. 



AGENTS USED FOR STERILIZATION 129 

The three previously named, carbolic acid, trichlorphenol, and mer- 
cury bichlorid, were the only ones that gave any satisfactory results, 
and these only partially so. In regard to the rest, Prof. Miller says: 
"They all fall far short of those already mentioned. The 10 per cent, 
solution of the peroxide of hydrogen came next to carbolic acid, but 
is considerably inferior to it. The essential oils, in emulsions as well 
as in pure form, utterly failed to produce the desired action." 

The results obtained by Miller are not wholly in accord with those 
of some others. Charles B. Nancrede, M.D., in an article 1 gives a 
list of agents which have "proved most reliable clinically, can be resorted 
to in any emergency, or are peculiarly applicable to meet exceptional 
indications :" 

Marked inhibition. Complete inhibition. 

Mercuric chlorid 1 to 1,600,000 1 to 300,000 

Oil of mustard 1 to 333,000 1 to 33,000 

Thymol 1 to 86,000 

Oil of turpentine 1 to 75,000 

Iodin 1 to 5,000 1 to 1,000 

Salicylic acid 1 to 3,300 1 to 1,500 

Eucalyptol 1 to 2,500 1 to 1,251 

Borax 1 to 2,000 1 to 700 

Potassium permanganate 1 to 1,400 

Boric acid 1 to 1,250 1 to 800 

Carbolic acid 1 to 1,250 1 to 850 

Quinin 1 to 830 1 to 625 

Alcohol 1 to 100 1 to 12.5 

At the time these tables were prepared one agent not mentioned was 
practically unknown as an antiseptic — formaldehyd, or in solution 
known as formalin. 

Dr. Elmer G. Horton, B.S., assistant in bacteriology, Department 
of Hygiene, University of Pennsylvania, undertook, at the request of 
Dr. Edward C. Kirk, a series of investigations with formaldehyd, 2 the 
results of which are given, omitting the details of experiments 

"We employed the gas generated by heating over an alcohol lamp 
a pastil which contained five grains of paraform. The lamp was placed 
in a tin box of nearly one cubic foot capacity . . . (Fig. 96). Among 
the instruments employed in the tests were various chisels, excavators, 
and burs. These were boiled, shown by cultural method to be sterile, 
then either dipped into bouillon cultures or infected from selected cases 
found in the operative clinic of the Department of Dentistry, University 
of Pennsylvania. After infection each instrument was placed in a sterile 
tube and kept at incubator temperature (37.5° C.) for three hours . . . 
In a single test with moist instruments we found sterilization complete. 
After the infection and subsequent drying the tubes containing the 
infected instruments were separated into two lots, one to be subjected to 
the method of disinfection and the others to be kept as controls, by 

1 Treatment of Wounds: Antisepsis and Asepsis, Surgery by American Authors, Park, page 365. 

2 Dental Cosmos. July. 1898. 

9 



130 



ANTISEPSIS IN DENTISTRY 



which would be shown that no step other than the action of formal- 
dehyd destroyed the vitality of the germs. . . . After exactly ten or 
fifteen minutes, according to the experiment, the door was opened and 
the instrument quickly removed. . . . Each instrument (controls like- 
wise) was placed in a considerable amount of sterile bouillon and these 
cultures, together with the subcultures made from them, observed for 
at least one week. ... In all experiments a free growth developed 
from the controls. ... The disinfection of instruments purposely 
infected in the clinics from cases of caries, pyorrhea, and gingivitis was 
satisfactorily accomplished in every case. ... We concluded that 
infected dental instruments can be disinfected without injury in a closed 

Fig. 96 




Schering's formalin sterilizer. 

space of less than one cubic foot, by an exposure of fifteen minutes to the 
formaldehyd gas generated from a pastil containing five grains of para- 
form by heating the pastil over a proper alcohol lamp." 

In an article on the "Uses and Limitations of Formaldehyd in 
Dentistry," by Dr. F. W. Low, Buffalo, N. Y., 1 the effect of formal- 
dehyd gas is further given as shown by a series of experiments con- 
ducted by Dr. Thos. B. Carpenter, assistant bacteriologist to the Health 
Department of the City of Buffalo. Without entering into detail, the 
experiments consisted of two series, one of infected instruments and the 
other of clothing either of school children, of nurses, or of the doctor 
in the presence of contagion, to determine whether they could be thor- 
oughly sterilized by placing them over night in a wardrobe exposed to 
the fumigation of the lamp used. 



i Dental 



February, 1900. 



AGENTS USED FOR STERILIZATION 131 

The conclusion of Dr. Carpenter was that "This apparatus can be 
relied upon, after an exposure of from ten to fifteen minutes, to destroy 
thin layers of the common, non-sporulating pathogenic organisms." 

In regard to the second series of experiments with clothing, he says : 
"It is evident, therefore, that twelve hours' exposure to the action of 
this lamp in a closet 15.8 cubic feet capacity is sufficient for effective 
surface disinfection, the most resistant pathogenic bacteria being de- 
stroyed." 

A third series of experiments was undertaken with scaling instru- 
ments taken from the instrument cases from several operators, including 
that of Dr. Low. The result of this elaborate experimentation is thus 
summed up by the author: "Every set, except the one where the whole 
case was fumigated over night, produced some cultures; but not one set 
developed a culture cf pathogenic organisms." 

"The Low lamp consists of an asbestos-lined tray, or box, supported 
on legs (Fig. 97, A), with an opening in the bottom to admit the chimney 
of the lamp, the purpose of which is to conduct the fumes of the for- 
maldehyd gas into the tray and upon the instruments it is desired to 
sterilize. 

"The working parts of the lamp are shown in the illustration. An 
ordinary alcohol wick is drawn into the wick tube. To place the lamp 
(B) in operation, fill it with wood alcohol, grain alcohol being incapable 
of generating formaldehyd. Adjust the cone-shaped platinum coil so 
that it just touches the top of the wick. Light the latter; place on 
chimney, and after a few seconds' waiting blow out the flame. If the 
cone be in proper adjustment to the wick, it will be observed that the 
coil glows like a live coal, but there is no flame or dangerous heat. 

"Having the lamp in operation, as described, and the tray properly 
adjusted to set over it, as in the illustration, instruments may be placed 
in the tray and allowed to remain for ten minutes, a sufficient time to 
effect sterilization. When taken out they should be wiped dry with a 
surgically clean napkin or towel. 

"To stop the fumigation going on in the lamp, remove the chimney 
and slide the cage high up on the tube, so that the platinum cone no 
longer touches the wick, then allow it to cool before replacing chimney." 

While it is not difficult for the average dentist to use formaldehyd 
as a disinfectant, it will probably be considered a useless expenditure 
of time, and, therefore, boiling in water and soda for at least twenty 
minutes seems the more feasible and is equally certain in the results. 

The dentist who aims to keep only aseptic instruments should have 
two sets in daily use. When through with one patient the instruments 
should undergo the boiling process in preparation for the next. At 
the close of the day all instruments used should be thoroughly boiled 
and dried upon aseptic napkins and placed in the case. The possibility 
of infection from the latter must not be overlooked. The first and 



132 



ANTISEPSIS IN DENTISTRY 



second set, therefore, used the next day for the first time should be 
either boiled again or each instrument dipped into an antiseptic fluid. 
For this purpose the writer prefers a strong solution of hydronaphthol 
(8 grains to the ounce of alcohol) to the carbolic acid solution ordinarily 
used. With this care all danger of infection can be removed and the 



Fig. 97 




%^ 




Fig. 98 







dentist relieved of all legal responsibility. The combination sterilizer 
and hot-water heater for gas or alcohol, designed by Dr. George J. 
Paynter, seems to be a convenient arrangement for the office. 

Fig. 99 represents a very convenient and efficient sterilizer where 
the electrical current is established. It sterilizes with boiling water. 



AGENTS USED FOR STERILIZATION 



133 



The full capacity of this sterilizer is two quarts. It has rounded corners 
and all seams are eliminated, with the exception of one at the terminal 
end. This prevents collection of debris, and facilitates cleaning. It 
is provided with a tray for small instruments, and with nickel-plated 
hooks for lifting it. The lid is provided with a wooden knob. 

It can be run by the direct or alternating current, and will boil water 
in fifteen minutes. It is made of heavy copper, nickel plated outside 
and tinned inside. The equipment includes a six foot connecting cord, 
with terminals and plug. Its efficiency, simplicity, and ornamental 
character recommends it for the dental office where available. It is 
introduced by the S. S. White Dental Manufacturing Company. 



Fig. 99 




The preparation of the hands previous to operations is most per- 
plexing to the conscientious operator, whether this be in surgery or 
dental practice. In order that dental operators may be able to arrive 
at definite conclusions in regard to what may be required of them in 
their daily work, the following quotation is given from Nancrede's 
article 1 on the care required in hospital surgical practice: 

"Sterilized water as hot as can be borne should be employed. This 
must, of course, be never cooled by the addition of any but cold ster- 
ilized water. . . The nail brush, best made of vegetable fiber, must 
always be carefully rinsed after use and sterilized by heat for each 
operation. . . Although it is alleged that all soaps made by heat are 
sterile — indeed, that potash soap is an active germ inhibitor in the pro- 
portion of 1 to 5000 — yet it is the part of prudence to combine with the 
soft soap 5 per cent, of hydronaphthol or thymol, to insure that the 
soap itself is free from germs. After thoroughly rubbing into the hands 
and arms and under the nails abundance of soap, the nail brush and 



1 Loc. cit. 



134 ANTISEPSIS IN DENTISTRY 

hot water must be vigorously used, especially beneath and around the 
nails, for from two to five minutes. Next, carefully clean the nails and 
around them with a nail cleaner. Removal of all grease can now be 
effected by ether or by immersion in alcohol, or best by alcohol contain- 
ing 5 per cent, of dilute acetic acid, which should be rinsed off thor- 
oughly with sterilized water, removing the last traces of soap. Finally, 
the hands should be immersed — not merely dipped — in a 1 to 2000 mer- 
curic chloride solution for not less than three — preferably five — minutes. 
Instead of corrosive sublimate solution, ordinary mustard flour mixed 
in the hands into a thin paste with sterilized water, used with gentle 
friction for two or three minutes and then removed with sterilized 
water, will prove a most successful germicide." 

While the foregoing may serve as a basis for comparison, it would 
be wholly impracticable in dental practice. It remains, however, that 
the hands of the dental operator should be the subject of constant care. 
Nails should be kept short and scrupulously clean. 

The importance of this to the dentist cannot be overstated, and it 
is probably the one precaution most neglected. The fingers are, 
necessarily, continually in the mouth of the patient, and nothing dis- 
turbs a cleanly person more than ill-kept nails, possibly loaded with 
infectious matter. Nails should be closely cut and the surrounding 
tissue well cared for by brush and antiseptic solutions. 

It seems to the writer that the use of a good potash soap and nail brush, 
with bathing the hands in alcohol, will be amply sufficient unless work- 
ing on a syphilitic patient, when more effective methods must be resorted 
to, and there can be nothing better than the mode described by Dr. 
Nancrede. 

The conclusions to which the writer has arrived from experience and 
study of the subject may be summed up briefly as follows: 

1. Dipping instruments in an antiseptic fluid previous to operating, 
while beneficial, is not sterilization. 

2. That boiling in water with soda added is for the dentist the 
most convenient means of sterilizing instruments without injury, while 
the more recently introduced method of formaldehyd antisepsis is a 
dry process that does not rust or injure steel instruments and is also 
promptly effective. The aqueous solution of formaldehyd (formalin, 
35 to 40 per cent.) is probably the best agent where simply dipping 
the instrument is desired. Two per cent, is of sufficient strength. 

3. That the ordinary methods used to effect sterilization in surgical 
practice are not possible in dentistry, but that every dentist is legally 
and morally bound to live as near to the rules of antisepsis as is possible 
with the demands of a daily practice. 



CHAPTEE IV 

EXAMINATION OF THE TEETH AND ORAL CAVITY 
PRELIMINARY TO OPERATION— REMOVAL OF DE- 
POSITS—APPLIANCES AND METHODS — RECORDING 

RESULTS 

By S. H. GUILFORD, A.M., D.D.S., Ph.D. 



Before undertaking the examination of the teeth it will be necessary 
to remove any calcic deposits that may be found upon the various tooth 
surfaces in order that every portion of the crowns may be open to 
inspection and instrumental exploration. 

This operation is usually known as "scaling," from the fact that the 
deposits are generally of a hard consistency, and when force is applied 
come away in scaly, fractured portions. 

The instruments employed are denominated scalers and are furnished 
in a variety of forms. Those of a sickle shape have met with the greatest 
favor, their peculiar form enabling the operator to reach conveniently 
more portions of the tooth surface than would be possible with an 
uncurved point. 

Fig. 100 



'1 



= 



1 



. i 

42 10 

Scaling instruments. 



39 



Some of these are shown in Fig. 100. Frequently, however, a large 
sized hoe or a spoon excavator will be found to operate more readily and 
expeditiously where large masses of the deposit are to be removed, as 
upon the lingual surfaces of the lower incisors and the buccal surfaces 
of the upper molars. 

In the removal of the hard deposits from the teeth great care should 
be exercised to avoid injury to the soft tissues and the infliction of un- 
necessary pain. 

(135) 



136 EXAMINATION OF THE TEETH AND ORAL CAVITY 

As the deposits usually terminate in an abrupt margin next to the 
gum, the edge of the instrument employed for removal should be caught 
above this ledge and drawn toward the occlusal or incisal surface with 
some force, so as to dislodge as large a portion of the material with each 
movement as possible. By repeated efforts of this character every portion 
of the deposit may be removed without tissue injury or bloodletting. 

With the exercise of care the operation of scaling need not be painful, 
except in the case of loosened and diseased teeth, and even then the 
discomfort may be greatly lessened by steadying with the thumb and 
forefinger of the left hand each tooth as it is operated upon. 

The teeth once freed from deposits, their examination should be pro- 
ceeded with. The importance of a careful and thorough examination 
can scarcely be overestimated, for failure to discover even a small 
lesion might result in subsequent serious consequences. In making 
the examination, certain instruments and accessories are necessary and 
should be at hand. 



Fig. 101 



/* 




®. .0" 

; ) I i 

'-'CO'"' 






*- •"'.- 



Record chart. 

Record Charts. — Charts consisting of a diagram of the teeth may be 
printed upon ordinary paper and fastened together in tablet form, or 
they may be printed upon heavier paper, or cardboard, and handled 
separately. Charts of different design are to be had, but the one shown 
in Fig. 101, designed by the writer, has answered every purpose; it 
represents both the permanent and temporary sets of teeth and each 
arch in its natural position. This enables the examiner to make his 
record more quickly and easily. 

Exploring Instruments. — These are delicate, tapering steel points, with 
spring temper and bent at an angle near the point. Those designed 
by Dr. Perry have met with the greatest favor. They come in a 
number of forms, fashioned into different angles and curves, as shown 
in Fig. 102. 



_ 



MAGNIFYING GLASS 



137 



The explorers are furnished either as solid instruments or as points to 
be screwed into a cone-socket handle, the latter being preferred because, 
when broken, they may be easily and quickly replaced. The first two 
shown in the illustration will serve all ordinary purposes, but the others 
are valuable in reaching points difficult of access. 



Fig. 102 



f 



ft' 



111 



o 



13 



14 15 17 

Exploring instruments. 




Mouth Mirrors. — These may be had either with a plain surface, which 
reflects the image in its natural size, or a concave surface, in which the 
image is magnified. Some prefer one form, some the other, but the 
majority of practitioners favor the use of the concave glass, since with 
the enlargement of the image we have also the magnifying of the defect, 
which enables it to be more quickly detected. 



Fig. 103 




Jeweller's eye-glass. 



Magnifying Glass. — To obtain a still further enlargement of the object, 
many operators use a magnifying glass of some form in addition to the 
mouth mirror. One known as the ieweller's eye-glass, shown in Fig. 
103, is probably the simplest and the most convenient form for dental 
examination. In use it is held between the thumb and forefinger of the 
left hand, about four inches from the object, and by its magnification 
surfaces of the teeth may be examined very quickly and accurately. 
Frequently the mouth mirror, held in the right hand and placed under- 



138 EXAMINATION OF THE TEETH AND ORAL CAVITY 

neath the tooth to be examined, throws a light upon the surface in such 
a way as to illumine it, and with the eye-glass on the opposite side, the 
illumination and enlargement are complete. By the combined use of 
the two glasses, cavities or partly disintegrated enamel are discovered 
which would have been missed by the ordinary means of examination. 

Silk Floss. — Silk floss is a very important accessory, as it enables us to 
detect any lesion or roughness on the approximal surface which has not 
otherwise been discovered. The silk should not be waxed, for if unwaxed 
the fraying of its fibers when passed between the teeth serves to indicate 
any unnatural condition of the surface. If waxed, no fraying would be 
likely to occur, the wax serving as a lubricant. The strands should 
not be too light nor yet too heavy; an intermediate grade being the best. 

Air Syringe. — An air syringe is a valuable adjunct in removing moisture 
from any surface of the tooth or between the teeth, thus enabling us to 
examine the parts more thoroughly. 

Absorbent Paper. — Thin Japanese absorbent paper or absorbent 
cotton, together with delicate tweezers to assist in applying it to different 
surfaces for the purpose of removing moisture, should also be provided. 
With all these accessories at hand, the examination may be begun. The 
patient should be placed comfortably in the chair and the clothing pro- 
tected by a towel or a large napkin fastened around the neck. A glass 
of water should be provided and additional hand napkins placed upon 
the bracket table for the patient's use. 

Technique. — The positions where caries is most likely to be found are 
in the fissures and sulci, and upon the approximal surfaces, the latter 
requiring the greatest care in examination on account of their difficulty 
of access. In beginning the examination a general inspection of the 
mouth and teeth should be made with the mouth mirror, and the visible 
cavities and defects marked upon the chart with a pencil. The explorer 
should next be passed over every exposed surface carefully and also 
under the free margin of the gum. Occasionally cavities are found 
hidden under the gingival margin which would not be discovered unless 
revealed by the explorer. In examining the approximal surfaces they 
should be made as dry as possible with absorbent paper or cotton, 
followed by a blast from the air syringe thoroughly to dry the surface. 
The explorer should be introduced into the interproximal space with 
its point directed toward the occlusal surface; then, by passing it back 
and forth, every portion of the approximal surface may be examined, 
excepting the contact point. This should be followed by silk floss, 
passing it back and forth between the points of contact. Even after 
the use of the explorer and the silk it is well to inspect these surfaces 
with a jeweller's glass, for, while there may be no extensive disintegration 
of the enamel, there may be an altered condition of the surface, as 
evidenced by discoloration or a chalky appearance near to or at the 
point of contact, which will be revealed by the use of the jeweller's glass 



TECHNIQUE 139 

above and reflecting mirror below. In order that the examination may 
be orderly and nothing omitted, it is well to follow a definite plan. 

We may begin the examination at the median line of the upper arch, 
examining each tooth successively back to and including the third molar; 
then, by beginning again at the median line and passing around the other 
side in the same manner, we will have included all the teeth of the upper 
arch. The lower arch should then be examined similarly. As cavities 
or defects are found they should be marked upon the chart, and it is 
well even to note any disposition toward tooth disintegration that may 
be met with in the course of the examination. The electric mouth mirror 
has been recommended as an aid in examination, but it does not seem to 
be a necessary adjunct. It has its use in determining whether the 
pulp in a tooth is alive or not, but the mirrors previously mentioned 
are sufficient for the purpose of detecting any injury to tooth substance. 

In addition to marking upon the chart such new cavities as may be 
found, we should examine the condition of any fillings previously inserted 
and note whether or not they are fit to remain. If these are defective 
the fact should be noted upon the chart, and if in the course of the 
examination places are found where it cannot be definitely decided 
whether tooth substance has been injured or not, it should be noted 
for further examination. In addition to marking upon the chart the 
cavities found, it is well to indicate upon the figure of the tooth the 
apparent extent of the tooth injury; in other words, the pencil mark 
should indicate the relative size of the cavity. 

If it is desired to indicate at the same time the character of the filling 
material to be used in the various cavities, it may be done by the use of 
colored pencils, using a different color for each kind of material to be 
employed. The advantages of a chart record are various. It shows at 
a glance the extent and character of the services needed; it forms the 
basis for the estimating of time required or expense involved; by checking 
off each item as completed it will indicate the still unperformed opera- 
tions, and permit the selection at each sitting of such work as is fitted 
to the time set apart; in addition, it will be of service in showing to the 
patient the number and character of the proposed operations. 

If in course of the examination it is apparent that the patient has not 
been in the habit of giving proper attention to his teeth, a good oppor- 
tunity is afforded for instructing him in the matter, and impressing upon 
him the fact that if the proposed operations are to be lasting and efficient, 
it is quite important that personal care on his part shall contribute to the 
desired success. 



CHAPTER V 

CREATING INTERDENTAL SPACES PREPARATORY TO 
FILLING; GRADUAL SEPARATION; IMMEDIATE OR 
FORCIBLE SEPARATION 

By S. H. GUILFORD, A.M., D.D.S., Ph.D. 

In separating teeth to obtain space for operation upon their 
approximal surfaces, great care should be exercised to avoid injury 
to the soft tissues or undue irritation of the pericementum. The opera- 
tion at best is one which patients dread, on account of the soreness 
induced in the moving teeth. The teeth of children, either deciduous 
or permanent, are more easily and quickly separated, owing to the 
greater thickness of the pericementum and imperfect calcification of 
the alveolar septa, while the teeth of adults move more slowly and 
require greater time for their separation because of the lessened thick- 
ness of the pericementum and the greater density of the septa. 
In view of these facts the character of the force to be applied 
and the means of applying it must be suited to existing conditions. 
When wedging is very gradual it is accompanied by little irritation, 
and consequently the soreness is reduced to the minimum. Where it is 
more rapid the operation is attended with greater irritation and more 
pain. Various substances and methods may be employed to create 
interdental spaces; fibrous substances such as cotton, tape, wood, etc., 
operate by the absorption of moisture and consequent expansion; 
elastic rubber exerts resilient force and operates rapidly; mechanical 
separation by steel separators, while limited in its results, is direct in 
its operation and often very useful as an accessory method. 

Gradual Separation. — Cotton. — Cotton for separation can be used to 
the best advantage when a wisp of it is twisted and drawn between the 
teeth at their points of contact. It should be kept dry while being 
inserted, and when in place clipped close on the labial and lingual 
surfaces of the teeth; as its expansive properties are largely due to the 
absorption of moisture and are limited, it should be renewed each 
day until sufficient space is gained. The fibers may be constricted and 
expansion consequently increased by passing a silk ligature through the 
interdental space between the cotton and gum and around the pledget, 
then drawing it tight and tying in a knot — this tying of the cotton also 
serves to keep it in place more securely. A modification of this plan 
consists in wrapping or twisting the wisp of cotton around a silk liga- 
(140) 






GRADUAL SEPARATION 



141 



ture. After it has been drawn between the teeth the free ends of the 
ligature are passed around the mass as in the previous instance, and tied. 
Linen Tape. — This substance operates on the same principle as 
cotton, and is more convenient to handle and place in position. The tape 
should be thin and very little more than one-eighth of an inch in width; 
one thickness should be drawn between the teeth the first day, two on the 
second, three on the third, and so on until sufficient space has been 
gained. Some operators employ waxed tape for separating, but the 
unwaxed is preferable because it absorbs moisture rapidly and it is 
the expansion of the fiber from absorption of moisture that gives it its 
efficiency. As the tape is easy to grasp and manipulate, patients fre- 
quently can insert the subsequent thicknesses themselves after the first 
piece has been placed by the operator. While both of the foregoing 
methods of separation are slow, requiring four or five days to produce 
the desired result, they are almost painless on account of their slowness. 



Fig. 104 



Wood wedges. 



Wood. — Compressed hickory in the form commonly known as pivot- 
wood, or some softer wood, as bass-wood strips, can be used for wedging. 
The latter, in order to have its efficiency increased, should be cut into 
strips lengthwise and then compressed laterally by being passed between 
the rolls of a rolling mill. In introducing wood of any kind it should be 
whittled to a wedge (Fig. 104) and pressed firmly between the teeth to 
be separated. When in place and the protruding portions have been 
clipped off with a wedge cutter, the rough ends should be smoothed with 
a small corundum w T heel in order to avoid possible irritation of the lips 
or tongue. Like cotton or linen tape, the wood expands by the absorption 
of moisture, and as it has been compressed before introduction, its 
expansion is not only greater but more rapid. 

Cork. — On account of its compressibility and rapid expansion in the 
presence of moisture, cork is an admirable substance for the separation 
of teeth. The tenacity w T ith which it clings to the tooth surface is another 
advantage which it possesses, because it is less likely to become displaced 
than wood. Thin slices of good bottle cork may be used, and after being 



142 CREATING INTERDENTAL SPACES 

introduced between the teeth, should be clipped close with a sharp 
bistoury. As cork is lacking in strength it cannot be forced between 
teeth that are close together. A slight space must first be created by 
the use of some other material, and then the separation continued by 
pieces of cork of varied thicknesses. Although its operation is slow, 
cork is one of the least unpleasant substances to use so far as the 
patient's comfort is concerned. 

Elastic Rubber. — This substance operates more quickly in separating 
teeth than any other material used for gradual separation. Its resiliency 
is so great that when a strip of it is drawn between the teeth its effort to 
return to its original form causes it to operate incessantly until this is 
accomplished. Owing to its constant expansion, the teeth under its 
influence are rapidly moved apart, and as a result, irritation is often set 
up in the pericementum, accompanied by soreness of the teeth when 
touched. Because of its rapid action it is employed far more frequently 
than any other substance for the separation of teeth, and as the irritation 
brought about by its use is its only objectionable quality, this may be 
modified by beginning the separation with a very thin piece. If the 
teeth to be separated are in close contact, a narrow strip of medium 
rubber dam may be drawn between them to start the separation; after 
this has been in place for a day it can be followed by a somewhat thicker 
piece which may be allowed to remain for two or three days. 

A very convenient form of rubber is that known as French rubber 
tubing. It comes in various sizes, the thickness increasing with the 
diameter. Sections cut from the tubing and then slitted afford a very 
convenient means for introduction between the teeth. 

According to the writer's experience, the use of elastic rubber should 
be confined to the first stages of separation, to be followed by the use 
of cork or tape; in this way teeth may be separated with very little 
resulting soreness. As rubber is extremely slippery when moist, it is very 
liable to change its position in the act of separating, and to slip up and 
impinge upon the soft gum tissue of the interdental space; it has been 
known to bury itself under this tissue and create great irritation when 
the patient has remained away from observation too long. To avoid 
this possibility, when rubber is placed between the teeth it should 
never be allowed to touch the gum, and at the same time should not be 
clipped too close to the incisal or occlusal surface. 

The same caution should be exercised in the placing of any separating 
material between the teeth. Whatever substance is employed, we should 
endeavor to retain it in its proper position by any and every means 
at our command. At the same time the patient should be instructed to 
return at once to the office if it be found that the substance between the 
teeth has become loose or has shifted its position. Should the teeth 
show symptoms of extreme soreness after separation by any method, 
it may be relieved before operating upon them by placing some non- 



IMMEDIATE OR FORCIBLE SEPARATION 



143 



resilient substance like gutta-percha between them and allowing it to 
remain for a few days. In this way the space will be preserved and 
the teeth given time to recover from their tenderness. 

Base-plate Gvita-fercha. — Where large approximal cavities exist, and 
it becomes necessary to separate the teeth in order that their normal 
contour may be restored by filling, a very excellent method is to pack 
the cavities a little more than full with red or white base-plate gutta- 
percha. By the action of the opposing teeth in closing, the material 
will be forced farther between the teeth and thus separate them gradually 
and almost painlessly. This idea originated with the late Dr. W. G. A. 
Bonwill, who found it of the greatest value and claimed that in addition 
to separating the teeth, gutta-percha would force the gum tissue beyond 
the gingival margin and thus expose that portion of the cavity which 
is usually difficult of access. 



Fig. 105 



Fig. 107 




Fig. 106 



mm 




Perry separators. 



Capwell's " single-bow" separator. 



Immediate or Forcible Separation. — The earliest method of producing 
immediate separation consisted in driving wooden wedges alternately 
between the teeth at their points of contact and through the interdental 
space near the gingival margin. It was a crude and painful method, 
and later was superseded by steel separators acting upon the screw 
principle. One of the first of this type to be devised was the "double- 
bow" separator invented by Dr. S. G. Perry. It is shown both separately 
in Fig. 105 and in position in Fig. 106. The first one of the Perry 
separators was intended for use between the incisors, but as soon as its 
value began to be recognized, others of the same form were devised for 



144 CREATING INTERDENTAL SPACES 

use between the side and posterior teeth ; thus a set of six was placed upon 
the market which seem to meet all requirements of an instrument of this 
character. The Perry separator probably is used today more than any 
other mechanical separator ever devised. Another form of separator, 
shown in Fig. 107, and known as the "single-bow," was devised by Dr. 
G. C. Capwell. While it may be used between any of the teeth, it is 
more especially serviceable in the anterior part of the mouth. As will be 
noticed, it is extremely simple in construction, and when in position is well 
out of the way of the operator. The handle used to operate the screw 
is removable, which is a feature peculiar to this instrument. 

While the mechanical separator is sometimes regarded as a painful 
instrument on account of its rapidity of action, it really need not be a 
source of distress to the patient if the operation is not hurried. With 
one or two turns of the operating screw followed by a rest of a few 
minutes and this process repeated, a fair amount of space can be obtained 
in from five to ten minutes' time. It will not usually provide as great a 
space as that obtained by the slower methods, but a plan frequently 
followed is to do part of the separating by the slow method of expansion 
and then at the time of the operation gain a little more space by the use 
of the mechanical separator. It has also been observed that if the teeth 
should retain some of their soreness after gradual separation, the appli- 
cation of the mechanical separator and its tightening will immediately 
relieve such soreness and permit the operation to be performed painlessly. 

This is doubtless due to the paralyzing of the nerve fibers of the 
pericementum under the pressure developed by the rapid action of the 
screw. The mechanical separator can be used to great advantage in 
the separation of children's teeth since the greater thickness of the 
pericementum permits its more rapid compression. 



CHAPTER VI 

MODIFICATION OF DENTINAL SENSITIVITY BY DE- 
HYDRATION; TOPICAL MEDICATION; ELECTRICAL 
OSMOSIS; GENERAL ANESTHESIA 

By S. H. GUILFORD, A.M., D.D.S., Ph.D. 

As all normal dentin is sensitive, the term sensitive dentin is incorrect 
when used to designate hypersensitive dentin, which may be defined 
as an exaltation of the normal sensitiveness of dentin. The dentin 
which comprises the large bulk of the hard tissues of a tooth is covered 
by enamel on the crown and cementum on the root; therefore, in the 
condition of normality the only indication we have of the sensitiveness 
of dentin is that which we experience in the application of substances, 
usually food, either considerably above or below the normal temperature 
of the mouth. If, however, the enamel has been removed from a tooth 
in whole or in part, either by accident, mechanically, or by caries, the 
dentin is exposed and thus sensitiveness becomes immediately apparent. 
Normal dentin may become exposed to outside influence through 
erosion, abrasion, traumatism, or caries. When exposed by erosion or 
abrasion it may or may not be hypersensitive. Very often hyper- 
sensitiveness is observed in teeth where the enamel has been worn away 
from the point of the cusps or where, through gum recession, the cemen- 
tum has become exposed and gradually removed by friction. When 
enamel has been abraded, as by a clasp on a plate, its wearing through 
to the dentin is so gradual that when the latter becomes exposed it is 
not apt to be very sensitive; in this case the pulp, stimulated to new 
activity by the external irritation, has formed new dentin upon the 
pulpal wall to compensate for that worn away externally by attrition, 
which accounts for the lessened sensitivity. When a tooth has been 
invaded by caries there may be no actual exposure of the dentin to the 
air and other external influences, since the soft products of caries overlie 
and protect it, thus serving as a non-conductor. In the process of 
excavating a cavity, when the debris of caries is removed, actual dentinal 
exposure takes place and the cutting of the dentin in the continued 
excavation of the cavity is often found to be very painful. In such 
cases the dentinal fibrillse may have been exposed to the action of caries- 
producing influences, generally lactic acid, and become irritated thereby. 
This is especially true when the progress of caries has, been rapid ; when 
it is slower the pulp has opportunity to protect itself from irritating 
10 (145) 



146 MODIFICATION OF DENTINAL SENSITIVITY 

influences by the formation of secondary dentin on the wall of the pulp 
chamber opposite the point of irritation. In carious cavities the dentin 
is usually most sensitive at the junction of the enamel and dentin, while 
the layer of dentin immediately beneath the carious mass is more sensitive 
than that beyond it. In some cases even large cavities may be excavated 
with almost no pain, whereas in others of apparently similar character the 
slightest touch of the instrument will cause almost unbearable pain. 
So-called hard or dense teeth are less sensitive than others, owing to 
the lesser amount of protoplasmic matter in the tubuli. 



TREATMENT 

Remedies may be arranged in two classes. In the first are those 
that benumb or anesthetize the fibrillse in the tubuli, and in the second, 
those that chemically destroy the fibrillse to a certain depth. 

Remedies that Benumb. — Dehydration. — As moisture is necessary 
to enable nerve filaments to convey sensation to the nerve centres, 
absence of moisture will necessarily interfere with or prevent such 
transmission; therefore the simplest and most logical method of 
producing analgesia, in whole or in part, in a tooth cavity for 
the purpose of excavating, is to dispel the moisture from the walls 
of the cavity and from the tubuli which form such surfaces. It has 
been found that desiccation of a cavity either by ordinary exposure to 
the air for a length of time, or by subjecting it to a current of warm 
air will bring about a condition of immunity to sensation in propor- 
tion as such desiccation is thorough or partial. To best accomplish 
desiccation of the dentin, the rubber dam should be adjusted to the 
teeth and the greater portion of the carious mass carefully removed 
with spoon excavators; the cavity should be bathed with absolute 
alcohol, and then subjected to a stream of warm air applied in some 
convenient manner. The ordinary air syringe or chip blower may have 
its point heated in a flame, and then by forcing the air in the bulb 
slowly through the tube, a jet of warm air will be delivered in the cavity. 
By holding the nozzle of the syringe at the proper distance, and having 
learned by experience how much heat to apply, one can often inject a 
current of air into the cavity at nearly the same temperature as that of 
the tooth; but if the air, when it reaches the cavity, should be either 
perceptibly above or below the proper temperature, pain will be pro- 
duced. In some warm-air syringes the tube is provided with a hollow 
receptacle somewhere along its length, which, when heated, raises the 
temperature of the air within it before being directed into the tooth 
cavity. Neither of these methods is at all exact, and they are therefore 
liable to produce more or less pain in the act of dehydration. A better 
plan is to employ a syringe in which a coil of fine platinum wire is 



TREATMENT 



14: 



contained within the orifice; this coil is connected by wires through 
the body of the syringe with a source of electric current; in operation 
the resistance encountered by the current of electricity passing through 
the platinum coil heats it and maintains a steady temperature. Air 
forced over this coil and through the nozzle, especially air supplied from 
a receiver and under pressure that can be controlled, may be heated to 
a temperature that will approximate very closely that of the tooth, and 
therefore produce little or no pain. If the air passing from the nozzle 
of the syringe should be too warm, it can be modified by holding it a 
little farther away from the tooth, or if not warm enough, more heat will 
be delivered when it is held in closer proximity. 



Fig. 108 




Electric warm-air syringe. 



Fig. 108 represents an instrument of this character with a compressible 
bulb instead of an air supply from a receiver. The operation of desicca- 
tion should not be hurried; time must be allowed for raising the air to a 
suitable temperature, so as to cause as little pain as possible. In addition, 
the operation should be continued until the dentinal walls of the cavity 
have become perceptibly lighter in color, indicating that they have been 
robbed of their moisture. If desiccation is not carried to this point 
it will fail in its effectiveness; but if the moisture has been removed 
from the dentin to a considerable depth, as it may be if desiccation be 
sufficiently continued, sensitiveness will have become nearly or entirely 
obliterated. Whether we depend entirely upon dryness to relieve the 
hypersensitivity or not, it should always be resorted to, for it proves a 
most valuable preliminary where it is to be followed by medication of 
any kind. 

Another means of avoiding excessive pain in excavating is by the use 
of sharp instruments and burs. It is well known that a sharp instrument 
will sever sensitive tissue with less pain than a dull one, and this is equally 
true in the cutting of a substance like dentin, which contains a consider- 
able amount of organic matter. Burs cause pain in operating principally 
through dulness or through being held in contact with the cavity wall 
too continuously. They should not only be sharp, but run at high 



148 MODIFICATION OF DENTINAL SENSITIVITY 

speed and allowed to touch the surface very lightly as they revolve; 
this avoids the heat of friction and consequently lessens pain. 

Topical Medication. — Refrigeration by a spray of ether or ethyl chlorid 
will reduce the temperature of the sensitive tissue and benumb it, but 
this is a painful method and consequently not often resorted to. A 
constant stream of warm water slightly above the temperature of the 
blood, directed into the cavity during the operation of excavation has 
been found in many cases greatly to lessen the normal sensitivity of the 
part; but as it is inconvenient to use and very difficult for one to operate 
in the presence of this stream of liquid, the method has not been gener- 
ally adopted. Vapocain, a proprietary remedy consisting of a 15 per 
cent, solution of cocain in ether, found some favor a few years ago for 
reducing the hypersensitiveness of dentin previous to excavating, but as 
it was not efficient in a large number of cases it soon fell into disfavor. 
Cocain hydrochlorid in a 10 per cent, to 25 per cent, aqueous solution 
forced into the tubules sometimes produces a mollifying effect, but it is 
difficult to retain the liquid and apply pressure except in cavities of 
limited size and favorable form. 

The late Prof. W. D. Miller claimed good results from the following 
method: After removing the bulk of debris from a cavity, he packed a 
mass of vulcanizable rubber into it to take its form. Removing this and 
drying the cavity he placed within it a small portion of cotton, saturated 
with a 10 per cent, solution of cocain hydrochlorid. Replacing the mass 
of rubber in the cavity, he exerted pressure upon it in such manner as 
to force the solution into the tubuli and produce desensitization. By 
repeating the treatment at intervals during excavation, he was able to 
prepare very sensitive cavities with very little pain. 

Electrical Osmosis. — Another method of employing cocain is by having 
it carried into the substance of the dentin by means of electrical osmosis. 
This process, known as cataphoresis, consists in placing a solution of 
cocain on cotton in the sensitive cavity, and having it carried along the 
dentinal tubuli toward the pulp by means of a galvanic current. A 
battery is employed with the negative electrode inserted in the cavity, 
and the anode placed upon some part of the patient's body, as the hand 
or cheek. The current carries the cocain into the deeper portions of the 
tooth and anesthetizes it. While in this condition, which usually lasts 
for an hour or more, the tooth may be worked upon without any pain. 
For a while this method met with great favor because of the perfect 
results obtained, but later it was found to be a very slow method, often 
consuming more time than the operator had at his command, and 
occasionally requiring a second application in order to produce complete 
anesthesia of the tooth; in addition, the cocain in some cases penetrated 
to the pulp itself and devitalization followed. 

Cocain Analgesia. — A better method of using cocain for anesthetiza- 
tion consists in forcing a weak solution of it into the dentin of a tooth 



COCAIN ANALGESIA 



149 



by means of a powerful compound pressure syringe. Several instru- 
ments of this character are on the market, but that known as the Weaver 
is probably one of the most efficient. It is shown in Fig. 109. 



Fig. 109 




In use a small pit is drilled through the enamel to the dentin with a 
No. \ bur, the nozzle of the syringe being tapered to fit the pit accurately. 
After the barrel of the syringe has been charged with a 5 to 15 per cent, 
solution of cocain in water, the point is forced tightly into the pit in the 
tooth, and pressure brought to bear upon the plunger of the syringe. 
If the fit between the drill-pit and the nozzle point is accurate, and the 
pressure in the syringe is kept up for one or two minutes, it will be found 
that the dentin has become entirely anesthetized and can be operated 
upon without pain. As this method is much simpler than that of cata- 
phoresis, it has met with great favor. Some practitioners have hesitated 
to adopt the use of the syringe for fear of the anesthetization being 
carried so far as to result in pulp devitalization. There is, of course, 
this possibility if the pressure be continued too long, and also in cases 
where the resistance of the teeth to such pressure is less than normal, 
but those who have adopted the method and have become familiar 
through experience with the conditions that favor its employment are 
very loud in its praise. This method of injecting cocain is also fre- 
quently employed to desensitize dentin in the gradual approach to the 
pulp for its devitalization. Secondary dentin is difficult to penetrate on 
account of its greater density; sometimes several applications being 
required before anesthetization is accomplished. Still another method 
of relieving hypersensitivity of the dentin consists in injecting a 1 per 
cent, solution of cocain into the gum tissue overlying the apex of the 
root. This acts by paralyzing the sensory nerve leading from the pulp. 
Some practitioners claim very satisfactory results from its use. 



150 



MODIFICATION OP DENTINAL SENSITIVITY 



General Anesthesia. — This radical method of treatment, while very 
seldom called for, is of the very greatest value in cases where the 
hypersensitivity of cavities is so extreme as not to permit of the least 
progress in excavation, and where the nervous condition of the patient 
does not warrant the infliction of any pain whatsoever. In the induce- 
ment of this condition, some of the general anesthetics may be employed; 
several are serviceable, and the choice rests with the operator. Somno- 
form, a proprietary compound, consisting of ethyl- and methyl-chlorid 
and ethyl-bromid, has won favor in dental and surgical practice, and 
has been found to be reasonably safe in its anesthetic action. Chloro- 
form has been used on account of its rapid action and the freedom from 
nausea, but its unfavorable action on the heart in some cases should 
prohibit its use in dental practice. In the employment of ether only 
sufficient of the drug should be inhaled to induce partial or peripheral 
anesthesia. Frequently, while there is absence of sensation, conscious- 
ness is still present. 



Fig. 110 




Fig. 110 represents a simple appliance for convenient administration. 
It is a metal tube about one inch in diameter, with a convex termination 
at one end having a central opening about three-sixteenths of an inch 
in diameter. Into the other end is fitted a cap with an extension for 
holding in the hand. In use, the tube is loosely filled with cotton, upon 
which a quantity of the anesthetic is poured. After the cap is replaced 
the appliance is given to the patient with instructions to hold it to the 
nose and inhale. When the hand drops it is evident that muscular 
relaxation and partial anesthesia have been produced, and excavation 
can be proceeded with. When sensation returns the patient will 
have to repeat the inhaling to again produce anesthesia, when further 
operations may be resumed. By this mild administration the patient 
is absolutely relieved of all pain without any unpleasant effects. In 
this as in all other cases where insensibility is produced the operator 
must proceed with great caution, otherwise the pulp may be reached 
and injured without warning. The writer has had several cases in 
which he could accomplish nothing by the usual methods of desensiti- 
zation, but which were rendered amenable to treatment by partial 
general anesthesia. In ordinary practice it will be found that thorough 
desiccation under the rubber dam with sharp instruments delicately 
handled, and an occasional application of carbolic acid, will usually 



TREATMENT 151 

mitigate or relieve most of the pain in nine-tenths of all cases presenting; 
for the balance, where sensitivity is unusual, the high-pressure syringe 
and cocain will be found most effective. 

Remedies which Chemically Destroy the Fibrils to a Limited 
Depth, Preventing Transmission of Sensation, are the Common 
Cauterants. — Those principally used for this purpose are zinc chlorid, 
silver nitrate, carbolic acid, and the latter combined with potassium 
hydroxid. To cause coagulation or destruction of the tubular content, 
their efficiency depends upon the length of time they are applied, and 
all of them cause more or less pain. 

Zinc Chlorid is more irritating than the others, but by adding crystals 
of cocain to the zinc chlorid at the time of its application this effect 
may be modified. In deep-seated cavities it should not be employed on 
account of the danger of pulp irritation either at the time of application 
or subsequently. 

Carbolic Acid. — This drug may be applied in full strength to cavities 
of any depth without danger. It operates quickly but not to any great 
depth, and is the most generally used of all obtundents. Whenever used 
for desensitization the cavities should be dried as thoroughly as possible 
before application, for in this way the acid is not diluted to so great an 
extent by the water in the tubuli. Cavities sensitive to air after excava- 
tion are immediately relieved by the application of carbolic acid. It not 
only serves to counteract thermal shock after filling, but gives to the tooth 
a warm and comfortable feeling. For this reason many operators, as 
a precautionary measure, wipe all cavities with carbolic acid before 
filling. Another virtue possessed by carbolic acid is that of a sterilizer 
of dentin. 

Silver Nitrate. — This salt is slow in action and does not operate to a 
great depth; it cauterizes the contents of the tubuli and gives them a 
protective coating. It is useful on denuded dentin at the necks of 
teeth or exposed surfaces on the tooth crown. The discoloration pro- 
duced by its use is objectionable, but on all exposed dentin surfaces 
where it is not visible it is an admirable desensitizer. 

Robinson's Remedy. — This preparation is composed of equal parts of 
caustic potash (potassium hydroxid) and carbolic acid; it is sometimes 
useful in relieving sensitiveness in cavities, though it is generally preferred 
for application, like silver nitrate, to denuded surfaces, and operates by 
destroying the tubular contents. Some operators occasionally depend 
upon time and the presence of a filling to mitigate hypersensitiveness. 

Temporary fillings, the various zinc cements or non-conducting 
gutta-percha, will frequently produce a marked effect in this respect. 
After partial excavation and filling with some temporary material, it 
has been found that the tooth becomes less sensitive to thermal influences, 
and that after the temporary filling has remained in a cavity for several 
months, excavation may be resumed and carried forward with com- 



152 MODIFICATION OF DENTINAL SENSITIVITY 

parative comfort. The change in sensitiveness of a cavity brought 
about by the presence of a non-conductive filling was formerly attributed 
to a process of eburnation or solidification of the tubular structure, but 
more recent investigations indicate that it is due to a deposition of 
secondary dentin on the walls of the pulp chamber, thus increasing the 
mass of dentin through which sensation has to be conveyed. Usually, 
hypersensitive dentin needs to be treated at the time of its discovery 
during excavation so that the operation may not be needlessly delayed. 



CHAPTER VII 
TECHNIQUE OF CAVITY PREPARATION 

By THOMAS E. WEEKS, D.D.S. 

In the light of our present knowledge we must consider all cavities as 
the result of some pathological condition. We cannot consider a carious 
tooth as an individual apart from its fellows and its environment, or the 
cavity simply as a hole to be filled. We must study the mouth and 
teeth as a whole and endeavor to determine what abnormal or patho- 
logical conditions are responsible for the beginning of any particular 
cavity. 

We know that caries is the result of the breeding, growth, and life 
activities of certain microorganisms, that these microorganisms must 
be sheltered and protected, else they are destroyed or their action 
inhibited by nature's weapons against disease which are present in 
every mouth. 

We know that well-formed teeth, arranged in proper relation to their 
fellows, both as regards contact and occlusion, in mouths which are 
maintained in a clean, healthy condition, seldom decay. 

Assuming that the student's knowledge of dental anatomy is sufficient 
to enable him to recognize normal conditions, the following several 
points should be noted: (1) Form of the teeth; (2) their arrangement 
in the arch; (3) their proximal contact; (4) the interproximal spaces and 
embrasures; (5) occlusion; (6) the health of the gums, and especially 
the condition of that portion which should fill the interproximal 
spaces. 

Without a knowledge of what is normal we cannot recognize the 
abnormal. Unless we can determine how much we can improve existing 
conditions by our completed operation, the preparation of any given 
cavity will not be performed with that intelligence necessary to insure 
the best results. 

A perfect, well-formed tooth is one in which there are no structural 
imperfections which result in pits and fissures, having such form that 
when in position in the arch it will make perfect contact with its fellows 
(similarly well formed), i. e., a small contact point in the incisal or 
occlusal third in both labio-lingual and gingivo-occlusal aspects. If 
this form prevails, the result must be well-formed interproximal spaces, 

(153) 



154 



TECHNIQUE OF CAVITY PREPARATION 



with sufficient septum of alveolar tissue to support and nourish enough 
healthy gum tissue to properly fill the space. With such form we will 
have broad embrasures, which will insure the cleansing of all of that 
portion of the proximal surfaces not covered and protected by the gum 
septum in the movement of the food as it is forced rootward in the act 
of mastication. When we consider the cases on record where all of the 
teeth have been forced into improper occlusion by the imperfect occlusal 
form of one filling, the importance of the occlusion is apparent. When 
we have reached this point in our diagnosis it will usually be apparent 
that much of the unhealthy condition of the soft tissues, if any exist, is 
due to some of the faulty conditions in form already noted. When this 
is corrected and normal spaces restored, the tissues will resume a healthy 
appearance. If due to other causes, it is usually amenable to treatment 
detailed in another chapter. 

In order that the text may be intelligible we must . understand the 
language of its descriptions. The nomenclature employed is that 
adopted by the National Institute of Dental Pedagogics, which is based 
upon the suggestions of Dr. Black, and applies only to prepared cavities : 



REPORT OF COMMITTEE NATIONAL ASSOCIATION OF DENTAL PEDAGOGICS. 
CAVITY NOMENCLATURE 



All that is to be said in describing cavity preparation can be expressed by the use 
of the following nouns and adjectives: 



Cavity, 
Wall, 
Margin, 
Plane, 



Surface, 
Angle, 
Thirds, 
Embrasure, 



Labial, 
Buccal, 
Lingual, 
Proximal, 



Mesial, 
Distal, 
Incisal, 
Occlusal, 



Gingival, 
Axial, 
Pulpal, 
Subpulpal. 



CAVITY NAMES 



Cavities in the teeth take the names of the surfaces in which they occur. 



Cavity 



Simple 



Complex . 



Labial, 
Buccal, 
Lingual, 
Mesial, 
Distal, 
Occlusal. 
Mesio-incisal, 
Disto-incisal, 
Mesio-labial, 
Disto-labial, 
Mesio-lingual, 
Disto-lingual 
Mesio-occlusal, 
Disto-occlusal, 
Linguo-occlusal, 
Bucco-occlusal, 
Mesio-distal-occlusal , 
(Other combinations 
by the same rule.) 



TECHNIQUE OP CAVITY PREPARATION 



155 



WALL NAMES 

Labial, 
Buccal, 
Incisal, 
Occlusal, 
Lingual, 
Wall i Mesial, 
Distal, 
Gingival, 
Axial, 
Pulpal, 
Subpulpal. 

the names of the surfaces of the tooth which thev 



That wall of a cavity in an axial surface of a tooth that 
covers the pulp is called the axial wall. If the cavity is ex- 
tended to include the pulp chamber this wall takes the name 
of the wall of the pulp chamber. The bottom or floor of 
occlusal cavities is called the pulpal wall. If extended to 
include the pulp chamber it becomes the subpulpal wall. 



Rule, cavity walls take 
approach. 



Line (Axial) 



Angles ■ 



Line (Pulpal) 



Point 



Angles (Simple Cavities) 



Mesio-buccal, 
Mesio-lingual, 
Disto-buccal, 
Disto-lingual. 

Bucco-axial, 
Linguo-axial, 
Mesio-axial, 
Disto-axial, 

Bucco-pulpal, 
Linguo-pulpal, 
Mesio-pulpal, 
Disto-pulpal. 

4 

Bucco-gingival, 

Linguo-gingival, 

Mesio-gingival, 

Disto-gingival, 

Axio-gingival, 

(and combinations with 

occlusal wall). 

Mesio-buccal-pulpal, 
Disto-bucco-pulpal. 



Occlusal 
Cavities. 



Axial Surface 
Cavities. 



Occlusal Cavities. 



Axial Surface 
Cavities. 



Mesio-linguo-pulpal, 
Disto-lingual-pulpal. 



Point Angles (the union of three line angles) take their names from the surfaces 
forming them. In occlusal cavities there are four. 

In complex cavities on axial surfaces there is another horizontal line-angle, i. e., in 
axial cavities combined with occlusal, the one formed by union of the axial and the 
pulpal wall— axio-pulpal. 

■4 
Division into Thirds 

Cavities may be divided into thirds, for convenience in description, as teeth are 
divided. 

Names of Margins 



Margins • 



Mesial, 

Distal, 

Buccal, 

Labial, 

Lingual, 

Incisal, 

Occlusal, 

Gingival. 






156 



TECHNIQUE OF CAVITY PREPARATION 



Nomenclature of Simple Cavities 



Walls 



Occlusal Cavities 



Mesial, 
Distal, 

I' Buccal, 
Lingual, 
Pulpal. 



f Mesio-buccal, 

Line Angles ! Mesio-lingual, 

(Longitudinal) j Disto-buccal, 

Disto-lingual. 



Line Angles 

(Transverse) 



Cavo-surface 

Angles 1 



Point Angles 



Margins . 



f Mesio-pulpal, 

(Disto-pulpal, 
Linguo-pulpal, 
Bucco-pulpal. 

f Mesio-occlusal, 
J Disto-occlusal, 
i Bucco-occlusal, 
I Linguo-occlusal. 

f Mesio-bucco-pulpal, 
! Disto-bucco-pulpal, 
I Mesio-linguo-pulpal, 
I Disto-linguo-pulpal. 

f Mesial, 
I Distal, 
I Buccal, 
L Lingual. 



Labial, Buccal, or Lingual Cavities 



Walls 



Line Angles 
(Longitudinal) 



Line Angles 

(Transverse) 



Cavo-surface 
Angles 1 



Mesial, 

Distal, 

Gingival, 

Occlusal or Incisal, 

Axial. 

Mesio-axial, 
Disto-axial. 

Mesio-occlusal, 

Disto-occlusal, 

Mesio-gingival, 

Disto-gingival, 

Occluso-axial, 

Gingivo-axial. 

Based on the same 
rule as for occlusal 
cavities. 



fMesio-axio-gingival, 
Disto-axio-gingival, 
Mesio-axio occlusal, 
I Disto-axio-occlusal, 



Margins 



f Mesial, 

I Distal, 

I Gingival, 

I Occlusal or Incisal. 



Simple cavities on proximal surfaces have the same number of walls, angles, and 
margins as those on other axial surfaces, and are named similarly. 

With this basis all cavities, however complex, may be easily named and described. 



Cavity Classification, Nomenclature, and Preparation 



Pit and Fissure. 
(No extension for 
prevention) 



Classification 

Cavities in the lingual surfaces of upper 

incisors. 
Cavities in occlusal surfaces of bicuspids and 

molars. 
Cavities in the occlusal two-thirds of the 

buccal and lingual surfaces of molars. 

Cavities a f Cavities in the gingival third of the labial, 

buccal, and lingual surfaces. 

Cavities in proximal surfaces of incisors and 
cuspids which do not involve the mesial 
or distal incisal angle. 

Cavities in proximal surfaces of incisors and 
cuspids which do involve the mesial or 
distal incisal angle. 

Cavities in the proximal surfaces of bicus- 
pids and molars. 

Note. — Cavities occurring in consequence of arrested development are not in- 
cluded. 

This report was adopted by the Institute. 

1 Cavo-surface angle — An angle formed by a wall of a cavity and the surface of the tooth in 
which the cavity is situated. 



Smooth Surface 

(Extension for 

prevention) 



INSTRUMENTS 



157 



PREPARATION 

In cavity preparation there are four definite steps: 

1. Establishing outline of the cavity. 

2. Removing softened dentin (decay). 

3. Giving the cavity proper shape. This includes resistance form, 
retention form, and convenience form. 

4. Bevelling and smoothing the enamel wall. 



INSTRUMENTS 

The instruments used in cavity preparation are hand instruments — 
those held in and manipulated by the hand; and engine instruments 
— those held in a hand-piece and revolved by power. The power instru- 
ments or burs have the same advantage over hand instruments that the 
power planer has over the hand planer, but owing to the peculiar con- 
struction of the teeth, especially the enamel, there are many parts of the 
operation which may be more effectively and speedily performed with 




20 


1G 


65 3 


20 


20 


20 


9 




Darby- 


9 


9 




6 




Perry, 


12 


12 


2 








L 


R 


12 



hand instruments. The hand instruments used are chisels and exca- 
vators. Chisels are straight (Fig. Ill), oblique (Fig. 112) (this form 
is made in pairs, right and left), or double oblique (Fig. 113), and 
those in which the blade is at an angle with the axis of the shaft (Fig. 
114). Excavators are divided into three classes, according to the form or 
position of the blade: hatchets, hoes, and spoons, or discoids. Hatchet 
excavators are those in which the hatchet-shaped blade is at an angle 
with the axis of the shaft, with its edge in the plane of the angle (Fig. 
115). Hoe excavators are those in which the hoe-shaped blade is at an 
angle with the shaft, with its edge at right angles with the plane of the 
angle (Fig. 116). 



158 



TECHNIQUE OF CAVITY PREPARATION 



Spoons are either contra-angle hoes, with a rounded cutting edge, for 
direct cutting, or contra-angle rights and lefts, for side cutting (Figs. 
117 and 118). 

Discoids have a disk-shaped blade with a cutting edge around the 
whole periphery except where it is attached to the shank (Fig. 119). 
As the point to be operated upon is so frequently inaccessible to direct 
force, the necessity arises for oblique chisels or those which, like exca- 
vators, have the blade at an angle with the shaft. If the point to be 
operated upon can be approached so the force can be delivered in a 
straight line from the hand or mallet to the point to be cut, the handle, 
shank, and blade may have a common axis (Fig. 120 b). If the point 
to be operated upon is not accessible to direct force, i. e., when the force 



Fig. 120 




-a 



must be delivered from a point somewhere between b and d (Fig. 120), 
we must employ chisels of the oblique type or those with the blade at an 
angle with the shaft, or excavators. In instruments having angles, the 
angle between the shaft and blade is greater or less as the point of 
approach is far from or near to the line b (Fig. 120). 

Angles and curves between blades and shafts and in shanks are for 
the purpose of bringing the blade into direct action upon surfaces which 
are inaccessible to straight instruments. 

These angles are expressed in centigrades (Black), divisions of the 
circle into 100 equal parts; each part is called a centigrade (Fig. 121). 
If the shaft of an excavator is laid upon a line passing vertically through 
the centre of the circle, with the angle between the blade and shaft at 
the centre of the circle, the line which passes through the centre of the 
blade will indicate the degree of the angle in centigrades (Fig. 122). 

Excavators in common use have an angle somewhere between 6 and 
28 centigrades. It has also been found that those most universally used 



INSTRUMENTS 



159 



are those having angles 6, 12, and 23. These differences in angles 
divide all forms of excavators into three groups. The next point of 
difference between excavators is the variation in width and length of 
blades. The width may be expressed in tenths of a millimeter and the 
length in millimeters. Observation also shows that those most used 
have blades 0.12, 0.8, and 0.6 mm. wide, and 5, 3, and 2 mm. long. 



Fig. 121 



Fig. 122 



2 70 




270 



180~ 




Understanding these measurements, the dentist can accurately express 
in figures the width of blade, the length of blade, and the angle between 
the blade and the shaft so that any instrument maker can make the 
instrument desired from a formula. In writing a formula, the first 
figure expresses the width of the blade; the second, the length of the 
blade; and the third, the angle between the blade and the shaft (devia- 
tion from the axis of the shaft in centigrades). Arranging the hatchet 
and hoe excavators most widely used into three groups, the formula? 
appear as follows: 



2 


8 6 


12 


8 6 


12 8 


6. width of blade. 


5 


3 2 


5 


3 2 


5 3 


2. length of blade. 


6 


6 6 


12 


12 12 

Fig. 123- 


23 23 

-Hatchets. 


23. angle in centigrades 



\ 



I 



% ^ 



1 1 




12 


8 


6 


12 


8 


6 


12 


8 


6 


5 


3 


9 


o 


o 


9 


o 


3 


2 


§ 


6 


6 


.12 


12 


12 


23 


23 


23 



160 



TECHNIQUE OF CAVITY PREPARATION 




2 


8 


6 


12 


8 


6 


12 


8 


6 


5 


3 


2 


5 


3 


2 


5 


3 


2 


6 


6 


6 


12 


12 


12 


23 


23 


23 



There are two other hatchets which are almost indispensable in 
shaping the retention angle in the incisal third of proximal cavities in 
incisors and cuspids; these have an acute angle between the blade and 
the shaft. Their formula is as follows: 



5 3 

3 2 

28 28- 



-2 instruments. 



Fig. 125 



III 



5 3 

3 2 

28 28 



When the blade of an excavator is more than 3 mm. long and the 
angle is 12 centigrades or more, there should be two angles, one contra 
to the other (contra-angled). The rule for contra-angling is that the 
angles be so formed that the edge of the blade is in line with the central 
axis of the shaft, or when the handle is laid on a plane surface the edge 
of the blade will just touch the surface. In spoon excavators there are 
two types, the contra-angle spoon, or modified hoe, in three sizes, 
expressed by the following formulae: 

10 20 30 
3 4 5 
12 12 12— 3 instruments. 



INSTRUMENTS 



161 



Fio. 126 



^ ^ 



The other type is the contra-angle 
double plane, side-cutting rights and 
lefts: 

20 15 10 
9 8 6 
12 12 12—6 instruments. 

Fig. 127 




20 


20 


15 


15 


10 


10 


9 


9 


8 


8 


6 


6 


12 


12 


12 


12 


12 


12 


L 


R 


L 


R 


L 


R 



Chisels. — Chisels may be divided 
into two groups — straight and bin- 
angle (contra-angle). Three in each 
group will be found sufficient. The 
blades in both groups measure : 
20 15 and 10 wide 
9 S and 6 long. — 6 instruments. 



Fig. 128 



Fig. 129 




The binangles have an angle of 
6 centigrades. 
Another form of contra-angle chisels is the enamel hatchet. They 
are called hatchets because the width of the blade is in the plane of 
the angles, but they are chisels because the blade is of the chisel 
form. 
11 



162 



TECHNIQUE OF CAVITY PREPARATION 



They are rights and lefts, and are used as side-cutting instruments. 
Three pairs will be found useful, the formula for which is as follows : 

20 15 10 
9 8 6 
12 12 12.— 6 instruments. 



Fig. 130 



Fig. 131 





Two other forms of chisels which have not been reduced to formula are 
those known by Catalogue Numbers 47, 48, and 48 S (Fig. 131). Those 
instruments known as gingival margin trimmers are also chisels. They 
are contra-angled double plane side-cutting instruments. As the edge 
of the blade is at an oblique angle with the long axis of the blade, it is 
necessary to use another figure to designate this. This figure, which 
indicates the angle of the edge with the axis of the blade, is placed between 
the first and second figures. There are two groups of these instruments 
formed by the difference in the width of the blades, and the angle between 
the edge and the axis of the blade. Their formula is as follows: 

20 20 15 15, width. 

95 80 95 80, angle of edge. 

19 9 9 9, lengths. 

12 12 18 12, angle.— 8 instruments. 

Fig. 132 





20 


20 


20 


20 


15 


15 


15 


15 


95 


95 


80 


80 


95 


95 


80 


80 


9 


9 


9 


9 


8 


8 


8 


8 


12 


12 


12 


12 


12 


12 


12 


12 


L 


R 


L 


R 


L 


R 


L 


R 



INSTRUMENTS 



163 



These instruments are used in giving the final bevel FlG - 133 

to the gingival, buccal, and lingual walls of proximal 
cavities, especially in bicuspids and molars. 

Burs. — Burs are divided into two groups, indicated 
by the manner in which the blades are cut. 

Cavity Burs: Those having smooth leaves. 

Dentate Burs : Those having the leaves cross-cut or 
serrated (forming teeth) (Fig. 133). 

The first class or group (cavity bur) is divided into 
eight groups, indicated by the form of the point or 
head, as follows: Round or rose; oval; pear-shaped; 
bud-shaped ; inverted cone ; wheel ; fissure (square end) ; 
fissure (pointed) (Figs. 134 to 141). 

Second class or group (dentate burs) is divided into 
four groups: Round; pear-shaped; fissure, square end; 
fissure, pointed. There is still another form of dentate bur, the tapered 
fissure (Fig. 142). Both square end and pointed. All forms of burs are 
made in from six to eight sizes, varying from 0.4 mm. to 0.30 mm. in 
diameter. The sizes mostly used, however, are 0.4, 0.6, 0.8, 0.10, and 



Fig. 134 Fig. 135 Fig. 136 Fig. 137 Fig. 138 Fig. 139 Fig. 140 Fig. 141 




0.12 mm. in diameter. Burs are catalogued by number, but it is apparent 
that more accuracy would be attained if manufacturers would designate 
and dentists would order, by the diameter of the head, indicated in tenths 
of a millimeter. This is simple if one possesses a Boley micromillimeter 
gauge (Fig. 143). This instrument is so useful for many other purposes 
that every dentist should possess one. Dentate burs are designed for cut- 
ting enamel. They are made in four forms, as follows : Round ; pear- 
shaped; fissure, square end; and fissure, pointed. They are made in six 
sizes, but the writer finds that the pear and the fissure, both square end and 



164 



TECHNIQUE OF CAVITY PREPARATION 



pointed, in two sizes, are the most useful (Fig. 144). There are some 
places, however, where the tapered fissure is very effective (Fig. 142). 
Cavity burs are designed for cutting dentin, and are made in eight forms, 
with from eight to twelve sizes in each form. Here again the writer 



Fig. 142 



«3=s_ 



D 



Fig. 143 





Fig. 144 



Boley's micromillimeter gauge. 

Fig. 145 





580 581 568 569 557 558 



X A 2 



33H 34 35 36 38 49 51 56 57 85 



Fig. 146 



I 





selects four forms, as follows: 4 round, 5 inverted cone, 2 bud, and 
3 square-end fissures (Fig. 145). 

Disks, Wheels, and Points. — These are sold under the trade names of 
Carborundum and Gem. Also small metal disks charged with Carbo- 



INSTRUMENTS 



165 



rundum or diamond dust. Disks are effective in opening fissures. 
Small wheels and points are very useful in extending enamel walls and 
shaping cavities for inlays. The most useful forms are shown in Fig. 
146. All of these instruments must be kept wet while in use. The 
selection and manner of using instruments will be treated more fully in 
the text of cavity preparation. 

Fig. 147 




In Nos. 1, 3, 4, 5, and 7 are shown typical cavities which occur on the lingual surfaces of the 
upper incisors and cuspids. When prepared as in Nos. 2, 6, and 8 the outline is established to 
include all sulcate grooves, the cavity in the dentin, which has been given the mortise form, and the 
enamel walls bevelled sufficiently to give strength to the cavo-surface angle. 

The writer believes that the student should be taught in his technique 
course how, when, and where to use the bur; he will thus appreciate 
the uses and relative value of both hand and engine instruments and will 
not attempt enamel cutting and other unwise uses of the engine when 
he comes to operate on the patient. 



166 



TECHNIQUE OF CAVITY PREPARATION 



PREPARATION OF CAVITIES BY CLASSES 

First Step. — Pit and Fissure Cavities. — These occur on the lingual 
surfaces of upper incisors and cuspids. The lingual surface of upper 
molars, the buccal surfaces of lower molars, but most frequently on the 
occlusal surfaces of all the bicuspids and molars (Figs. 147, 148, 149, 150, 
and 151). As these cavities are usually confined to the surfaces upon 
which they begin, they may be considered as inlays, as this term is applied 
in mechanics; their outline varying as influenced by the form and 
markings of the surface upon which they occur. 

Fig. 148 




The lingual surfaces of the upper molars, especially the first molar, frequently show cavities, as in 
Nos. 1 and 2. The preparation, as in No. 3, follows the same rules as those given in Fig. 147. 



In carpentry, the general form of the cavity for an inlay is the simple 
mortise (No. 1, Fig. 152). Several forms of its application to teeth are 
shown in Nos. 2, 3, and 4, Fig. 152. In many locations, because of the 
direction of the enamel rods, this simple form might result in leaving 
some enamel rods at the margin of the cavity unsupported by dentin. 
Fig. 153 (modified from Noyes) shows how this might occur. This con- 
dition is overcome by laying that portion of the wall formed by the 
enamel in a different plane from that formed by the dentin (Fig. 154). 
Fig. 155 shows a similar cavity, in which the dentin and enamel walls are 
in the same plane. A careful study of the sections shown will establish 



PREPARATION OF CAVITIES BY CLASSES 



167 





Fig. 149 




1 


2 


3 


n*^ 


^ j JHF* 


H^'* 


I 




& 1 1 

B 3 1 



In the lower molars, especially the first molar, cavities occur in the buccal grooves, Nos. 1 and 2. 
In No. 3 is shown the preparation when the cavity is confined to the terminal fossa. In cavities 
like Nos. 1 and 2 it would be necessary to extend the cavity to the occlusal surface, connecting it 
with the occlusal filling, if one be present. 



Fig. 150 



©ee§ 



eeee 



5 6 7 8 

The teeth from which these pictures were made, as well as all of those having cavities, that appear 
in the other plates, were selected from a large number of teeth similarly decayed, as being typical 
of their class. If lines are drawn to include all sulcate grooves and give a graceful outline, the size 
and form of the prepared cavity will be indicated. (See Fig. 162.) 



168 



TECHNIQUE OF CAVITY PREPARATION 

Fig. 151 



T % j -•■••■ 9 

I .m* 1 • 




I^JH 




^ M - ■ • . 

Hta«^B . 

US HB 

■ •. : . l • 3 m 

' ■ ■'■ S v . ? 
■•••■'. 1 • - fl 








r^ ,-«4m • • 858 •• 


^NKf 


||B • ■ »-- x '?i 


^3il5^^^^^^^aK 


L A-'< 












5 b / o 

These pictures will repay careful study. They are not extremes, only types. Draw outlines 

include all sulcate grooves, and at the same time preserve all the cusp formation possible. (See 



to include 
Fig. 162.) 



Fig. 152 




No. 1 shows the simplest form of mortise employed in mechanics. No. 2 is presented, not to 
show a practical cavity, but to bring out the modification necessary to establish the proper 
"bevel" of the enamel wall. No. 3 shows a common type of the simple mortise as applied in a 
lower second molar. No. 4 illustrates the modification necessary to include all susceptible areas. 
It is still a simple mortise. 



PREPARATION OF CAVITIES BY CLASSES 



169 



Fig. 153 





















I'm 




































f 












% 




1 












1 




i 

1 




/'\ 






















£ \ 
























. 























This excellent section, reproduced from a photograph in the writer's possession (by Dr. F. B. 
Noyes), shows the condition of the enamel rods if cavity walls were laid at any point parallel with 
the vertical lines. A study of this picture will indicate the line of bevel necessary to protect the 
enamel rods at any point between the sulcus and the summit of the cusps. 



Fig. 154 



Fig. 155 





This section shows the simple mortise form 
of cavity in the dentin with the enamel walls 
properly bevelled to protect the enamel rods. 



This section shows a cavity where the dentin 
walls and the enamel walls are in the same 
plane. This form of mortise is permissible 
where the walls are so located that the enamel 
rods will be protected when the enamel walls 
are in the vertical plane. This, or some slight 
modification, is necessary when amalgam is 
used. 



170 



TECHNIQUE OF CAVITY PREPARATION 



the fact that in the preparation of all cavities we have to deal with two 
distinct substances, dentin and enamel, and that it is in the dentin that 
we secure the seat or anchorage for the rilling. Also, that the structure 
of the enamel makes it necessary that it should be so cut that the rods at 
the cavo-surface angle will rest upon sound dentin. If we divide the 
walls of a cavity into two parts and think of that portion in the dentin 
as ''dentin wall" and that part in the enamel as "enamel wall" it will 
simplify our procedure. 




These sections were made from teeth in which the surface indications were no greater than in the 
smallest cavities shown in Figs. 150 and 151. They illustrate the behavior of caries after the enamel 
has been penetrated. 



In No. 2, Fig. 152, is shown the application of the simple mortise to a 
cavity in a lower second molar. Sections of similar teeth show how the 
direction of the enamel rods modifies the simple mortise (Figs. 156 and 
157). Following the prescribed order of procedure, we first open the 
cavity and establish its outline. In those cavities where caries has not 
progressed so far as to leave the enamel unsupported, it is best to open 
and extend the fissures with dentate burs, either pear-shaped or pointed 



PREPARATION OF CAVITIES BY CLASSES 
Fig. 157 



171 




5 6 7 

These sections are from some of the teeth shown in Fig. 151, and are offered as instructive exam- 
ples of the interior spreading of caries. Note the cutting necessary to establish strong enamel 
walls in some of them. 



Fig. 158 



u 




This cut shows a worn fissure bur which 
has been converted into an effective drill for 
extending fissures, by bi-bevelling the point. 



This cut shows the manner of using a drill 
made from a worn fissure bur, in opening and 
extending fissures. 



172 



TECHNIQUE OF CAVITY PREPARATION 



fissure (Fig. 133). Partially worn fissure burs may be made into effective 
instruments by bi-bevelling the end, forming a drill (Fig. 158). If the bur 
is entered in a pit to the dento-enamel junction, and the cutting done 







Fig. 160 






y'- 


■w 




/, 












jA 


hi i • m ^^' l *^^__ 



Manner of holding an instrument by the "pen" grasp, and the position of the fingers to provide 

a ' 'rest." 



Fig. 161 




Manner of holding an instrument by the "palm " grasp, with the position of the thumb to provide 

a "rest." 



from within outward, it will expedite the work, as enamel cuts much 
easier in this way (Fig. 159). 

After the cavity is opened in this way, or by the extension of the 
caries, the unsupported enamel is split off with chisels. While these 



PREPARATION OF CAVITIES BY CLASSES 



173 



may be used by hand pressure alone, it is usually best to employ the 
hand mallet, as much larger pieces may be split off in this way with 
less discomfort to the patient. In the use of chisels there are two prin- 
cipal grasps — the pen grasp (Fig. 160) and the palm and thumb grasp 
(Fig. 162). With either of these grasps, rests and guards are necessary. 
The illustrations will show the manner of using the third and fourth 
finger in the pen grasp, and the thumb in the palm grasp. The rule for 
cavity outline in these pit and fissure cavities is that all pits must be 
extended until the enamel rods at the margin of the cavity rest upon 
sound dentin and no sulcate grooves radiate from the cavity margin. 
All fissures must be extended until they become grooves. A study of 
Figs. 148, 149, 150, and 151 will show the amount of extension which is 
necessary. 



Fig. 162 
2 




These figures illustrate a safe preparation of some of the cavities shown in previous plates, and 
show the application of the simple mortise. 



Here let us recall the definition of certain terms (from Black) : 

Fossa (plural Fossae) : A rounded or angular depression in the surface 
of a tooth. 

Pit: A sharp-pointed depression in the enamel. 

Groove: A long-shaped depression in the surface of a tooth. 

Sulcus (plural Sulci) : A notably long-shaped depression in the surface 
of a tooth, the inclines of which meet at an angle. A sulcus has a 
developmental groove at the junction of its inclines. 



174 TECHNIQUE OF CAVITY PREPARATION 

Fissure: A fault in the surface of a tooth caused by the imperfect 
joining of the enamel of the different lobes. 

In such cavities as occur from faulty union of the enamel along devel- 
opmental lines in what would normally be fossae and grooves, it is only 
necessary that the walls be extended until all enamel unsupported by 
dentin is removed and until the margins are unbroken by sulcate 
grooves leading off from them, which would prevent the perfect finishing 
of the margins of the filling. 

These rules have been observed in the preparation of the cavities for 
the illustrations (Figs. 152 and 162). 

Second Step. — Removal of Softened Dentin. — After the cavity is 
opened all softened dentin should be removed with spoon or discoid 
excavators (Figs. 117, 118, 119). These are usually held by the pen grasp 
(Fig. 160) . The first cutting is made with a sweeping motion, first to the 
right and then to the left, around the cavity, just below the dento-enamel 
junction; the deeper portions can then be removed with a lifting motion 
of the blade. When we begin to operate upon the dentin the whole 
picture of its structure should rise before us, especially the intimate rela- 
tion of its organic portion, the fibrillar, with the pulp and the possible 
change in its structure as the result of caries. (See Chapter II.) When 
a cavity presents, the first thing is to ascertain its extent, how much 
dentin is already destroyed. To do this we must perform the first two 
steps. Then and only then can we determine intelligently what the 
outline of the cavity must be. When we discover that in a majority of 
cases this can be done with chisels and excavators alone, better and 
easier for the patient, than with the engine, we shall have gained much in 
the esteem of the patient and in ability as an operator. Figs. 163, 164, 
and 165 show occlusal cavities with outline established and decay 
removed. 

Third Step. — Shaping the Cavity for Resistance, Retention, and Con- 
venience. — When the form of the cavity is established as indicated by the 
extent of the caries and the cutting necessary to remove faults in the 
enamel and insure perfect margins in the completed filling, it remains 
for us to determine how much this form must be changed to meet the 
above requirements. 

When the first two steps have been carefully and thoroughly per- 
formed, many cavities need but little modification to provide the neces- 
sary resistance, retention, and a form convenient for the insertion of a 
filling (Figs. 163, 164, and 165, and No. 1, Fig. 166). All cavities of this 
type may be considered as simple inlays, the fault or hole to be stopped 
with a mass formed to fit the prepared cavity and inserted en masse. 
Having mastered these principles, it becomes easy to modify forms to 
meet the demands of the various materials and methods employed. 
Remember, that now we are considering only simple cavities, those 
confined to one surface, and having continuous surrounding walls. In 



PREPARATION OF CAVITIES BY CLASSES 



175 



No. 4, Fig. 152, we see the form the mechanic would make, the depth of 
his cavity varying to meet the demands determined by the nature of the 
material employed and the amount of stress to which the completed 
operation is to be subjected. This is what governs us in the amount of 
resistance and retention form we give to our cavities. 



Fig. 163 



Fig. 164 





Fig. 165 




These sections show the form of cavities after the unsupported enamel has been broken down 
and the softened dentin removed. This comprises the first two steps in cavity preparation. 

Referring again to the occlusal cavities in bicuspids and molars, we 
find that all the stress save that exerted by such adhesive substances as 
sticky candy, etc., which occur in the food, falls within a radius of 180 
degrees (Fig. 120). 

Reference to sections of the teeth, appearing in the illustrations, shows 
that the position of the pulp regulates the depth of the cavity which it is 



176 



TECHNIQUE OF CAVITY PREPARATION 



safe to establish in vital teeth. A rule has been promulgated that the 
depth of a cavity having parallel walls, should be equal to its diameter 
(No. 2, Fig. 166, and No. 2, Fig. 167). When this is not possible, we may 



Fig. 166 



WLl 



12 3 

No. 1 shows an occlusal cavity in a bicuspid after the enamel walls have been sufficiently extended 
and all softened dentin removed. No. 2 shows the depth of cavity, as compared with the diameter, 
necessary to provide sufficient retention when the walls of the cavity are parallel in both dentin 
and enamel. No. 3 shows the dovetail form in the dentin to provide additional retention, with the 
enamel walls in a distinctly different plane, to insure protection to the enamel rods. 



Fig 




1 2 

No. 1 shows the enamel bevel which is necessary when gold is the material used for the filling. 
No. 2 shows an amalgam filling. This cavity has the enamel walls in the same plane with the 
dentin walls in order that the margins of the filling may be protected from fracture. 

resort to the dovetail form (No. 3, Fig. 166, and No. 1, Fig. 167). Refer- 
ring again to the sections, it will be seen that in the majority of cavities 
the enamel walls must be divergent, i. e., in a different plane from the 



PREPARATION OF CAVITIES BY CLASSES 177 

dentin walls; consequently, the retentive form of the cavity is confined 
to the dentin. 

In mechanics, when the simple mortise is insufficient to furnish the 
necessary resistance, the dovetail mortise is employed. Where the 
filling is inserted in a plastic form or built in piecemeal, as with gold 
or tin, this form is easily filled; but when the filling is inserted en masse, 
as in an inlay, the dovetail form must be made after the inlay is fitted, 
and the cementing substance depended upon to key the piece against 
stress, if necessary. In most cases where decay has not destroyed suffi- 
cient dentin to allow a proper depth to permit parallel walls (where 
diameter is greater than depth), it is necessary to employ the dovetail 
form, i. e., to make the dental walls convergent as they rise from the 
pulpal wall or floor of the cavity (No. 3, Fig. 166, and No. 1, Fig. 167). 
It is not always necessary that the dovetail form be given to all of the 
walls. It is often sufficient to apply it to only two opposite walls. 

Instrumentation. — As the box or mortise form results in definite angles 
at the junction of the peripheral walls with the pulpal or axial wall, it 
is necessary to employ instruments the edge of which is at right or acute 
angles with the axis of the blade; such instruments are the hatchet and 
hoe excavators (Figs. 123 and 124). In burs, the inverted cone and 
the square end fissure are indicated. 

In using burs in dentin in vital teeth it will be found much less pain- 
ful and quite as effective to use the small sizes. In establishing the proper 
form it is best to get the shape roughly with burs, smoothing the walls 
and defining the angles with excavators. 

If the " convenience points" recommended by Black are indicated, 
they are best formed with small inverted cone burs (Fig. 145). 

Bevelling and Finishing Enamel Walls. — The bevel or plane of the 
enamel walls is indicated, first, by the direction of the enamel rods at 
the border or margin of the cavity; second, by the character of the 
filling material. Observation of the line of cleavage as the enamel splits, 
when using the chisel, will indicate the bevel or inclination of the enamel 
wall necessary to insure that the rods at the cavo-surface angle rest upon 
dentin and that they are supported by a buttress of shorter rods which 
are covered and protected by the filling or inlay. (See sections shown in 
illustrations.) In inlays or fillings of gold, which possess ductility, 
tenacity, and edge strength, the margins of the filling may show more 
acute angles in section without danger (No. l,Fig. 167). When porce- 
lain, tin, amalgam, or cement is used, it is necessary to modify the incli- 
nation or bevel, that the angle shown in section may be sufficiently 
strong to avoid the danger of fracture or chipping of the filling under 
stress (No. 2, Fig. 167). These conditions may make it necessary to 
extend the enamel walls at certain points beyond the lines indicated by 
the rules for establishing outlines, already noted. 

Whatever the inclination of enamel walls, they should always show a, 
12 



178 TECHNIQUE OF CAVITY PREPARATION 

true plane at any point in section. (See prepared cavities in section.) 
A short supplemental bevel of the occlusal fifth of the wall (cavo-surface 
angle) may be given to insure the buttressing already referred to. 

Instrumentation. — The final shaping and finishing of enamel walls is 
best accomplished with chisels and gingival margin trimmers. These 
must be razor sharp. Fine grinding stones and disks may be used, but 
the danger is always present of destroying the plane surface — definitive- 
ness of the cavo-surface angle — leaving the wall rounded as in No. 1, 
Fig. 166. This must be avoided, because it is impossible to properly 
finish the margins of a filling under these conditions. The most useful 
forms of chisels are those shown in Figs. 129, 130, 131, and 132. 

Final Touches to the Cavity. — As freshly cut surfaces are clean, it fol- 
lows that the final cutting of all walls should be done after the application 
of the rubber dam or some other equally efficient means of excluding 
the fluids of the mouth. When the instrumentation is complete, all 
surfaces should be carefully wiped with cotton, spunk, or bibulous 
paper. The practice of flooding the cavity with drugs for their supposed 
antiseptic value is unnecessary if the cavity is properly prepared — all 
decayed dentin removed. If asepsis cannot be secured by instrumenta- 
tion alone, the cavity should be sterilized before the final preparation 
of the enamel walls. When the cavity is to receive an inlay, the walls 
should be protected in the interim between the preparation of the cavity 
and the cementing of the inlay, by a temporary stopping and finally 
washed with alcohol or ether. A safe rule is never to permit the contact 
of the fluids of the mouth or any viscid or oily substance after the final 
preparation. 

SMOOTH SURFACE CAVITIES 

Cavities in the Gingival Third of Labial, Buccal, and Lingual Surfaces of 
the Teeth. — As these cavities are confined to one surface, they have con- 
tinuous surrounding walls, and come under the class of simple inlays; 
consequently, the rules for dentin form and enamel bevels are the same 
as in pit and fissure cavities. The cause for the occurrence of these 
cavities cannot be discussed here, but should be considered in establishing 
the outlines of the cavity. The extent of each cavity must be governed 
by the conditions existing in that particular case. Reference to Fig. 168 
will show that these cavities are not always confined to the gingival 
third. Even so, they may be distinguished from those cavities which 
have their beginning in pits and fissures, as this fact influences their 
outline (Figs. 147 and 148). The preparation of these cavities is shown 
in Nos. 3, 4, and 5, Fig. 168. 

Cavities in the Proximal Surfaces of Incisors and Cuspids Which do Not 
Involve the Incisal Angle. — These are shown in Figs. 169 and 170. These 
cavities should have their margins extended until they are so placed as 



SMOOTH SURFACE CAVITIES 



179 



to be easily cleansed. Specimens are shown in Figs. 171 and 172. When 
the cavity is opened it will present an appearance like Fig. 173. In com- 



Fig. 168 





^^TB r h 


r'^r^B.V 






[<■ 


R^^ 


1 Hi W 1 

W \ M 1 


1 gm 


1 tin^ a 




1) I 




fl ' '' 


1 


; 9tanJI : w jfi 







5 6 7 8 

Nos. 1 and 2 show the characteristic cavities which occur in the gingival third of the labial sur- 
faces of the teeth. Nos. 3 and 4 show the preparation of this class of cavities which will insure 
the best results mechanically and artistically. The lower group (Nos. 6, 7, and 8) offers a study 
of typical cavities which occur on the smooth portion of buccal surfaces, usually in the gingival 
third. In No. 5 may be seen a typical cavity preparation for this class of cavities. 



pleting the cavity form, the gingival wall is made flat in both horizontal 
planes, with the axial wall meeting it at a right angle. The labial and 
lingual walls meet the gingival at an acute angle. They also meet the 



180 



TECHNIQUE OF CAVITY PREPARATION 



axial wall at a slightly acute angle in the gingival third. This forms 
two acute point angles and gives retentive form in the base, or gingival 
third. 









Fig. 169 






1 


2 


3 


4 


5 


1 








^^^ | 


1 








^T * : J ' B 


1 , 






9 










1 B 


^m Iw 


j^| 








1 






V -'''W& 




. 






ft * ; ^ 


* H 


If 'A 


JO! 


1 




i- m 












■ ; 












■ 



G 7 8 9 10 

No. 1 shows a gold filling in which recurrent decay has begun at the labio-gingival and linguo- 
gingival angles. No. 2, Fig. 176, shows the cavity after the filling was removed, and No. 1 (same 
Fig.) is the writer's suggestion for a correct preparation, which should include the area of recurrent 
decay. Nos. 2 to 10 are offered for study as representing typical proximal cavities. 



The incisal anchorage is formed by making the labial and lingual walls 
meet the axial wall at right angles in the incisal third, but the point 
angle formed by their union is an acute angle with the axial wall. This 
gives the third leg of the triangular anchorage, which is well shown in 
Fig. 174 and in No. 4, Fig. 175. There are no undercuts or angles formed 
by the union of the labial and lingual with the axial wall in the middle 
third. No. 1, Fig. 169, shows a gold filling where recurrent caries is 



SMOOTH SURFACE CAVITIES 



181 



beginning at the labio-gingival and linguo-gingival angles. The original 
preparation of this cavity is shown in No. 2, Fig. 176. If this cavity had 
been originally prepared, as in No. 1, Fig. 176, recurrent caries would 
not have appeared. Fig. 177 shows labial and lingual views of this type 
of cavities. In establishing the labial margin of these cavities, care 



Fig. 170 



Fig. 171 






Fig. 170. — This section is from the tooth shown in No. 2, Fig. 60. and is worthy of study. 
Fig. 171. — Shows a typical preparation for cavities like those shown in Nos. 1 to 5, Fig. 169. 
Fig. 172. — A typical preparation for cavities in the lower incisors and cuspids, like those shown 
in Nos. 6 to 10, Fig. 169. 



Fig. 173 



Fig. 174 





Shows a cavity after the first two steps 
have been performed (establishing the outline 
and removing all softened dentin). 



Shows a cavity where conditions necessi- 
tated a little broader cutting. Observe that, 
no matter what the size of the cavity, the 
general form is the same. 



should be taken to avoid the semicircular form so often seen. There 
is a harmony of lines, as well as a harmony of sound and color, and the 
form shown in the illustrations is more in harmony with the general 
outlines of the teeth. The lingual wall should be carried far enough on 
to the lingual surface to include the linguo-marginal ridge. Experience 






182 



TECHNIQUE OF CAVITY PREPARATION 

Fig. 175 




No. 1 shows a tooth in which caries has resulted in sufficient loss of substance to demand extra 
incisal anchorage. No. 2 shows the first stage in preparation, and No. 3 a lingual view of the 
second stage. 1 No. 4 is a section showing the dovetailed form of two cavities where all of the 
incisal point anchorage is provided in an emphasized point angle, and is entirely within the cavity- 
walls. 

Fig. 176 




1 2 

No. 2 shows the cavity as originally prepared for the gold filling shown in No. 1, Fig. 169. No. 1 
shows the writer's preparation of the same cavity. (It was prepared in the same tooth, there 
being no recurrent decay in the cavity.) 

> The writer uses this term to indicate the order in which a compound cavity is prepared, and 
should not be confused with "step." The forming of the main cavity is the first "stage," and the 
' 'step" is formed in the second ' 'stage." 



SMOOTH SURFACE CAVITIES 



183 



has shown that recurrent caries is frequent where the lingual wall is left 
well within the lingual embrasure. 




Fig. V t 




No. 1 shows the labial and No. 2 the lingual outline 
of average cavities which do not involve the incisal 
angle. This form is more in harmony with the general 
outlines of the teeth than the semicircular form so 
often seen. 

Fig. 179 



Shows the application of the 
"dovetailed mortise" to a cavity 
in a cuspid tooth. This form is 
applicable in teeth having short, 
thick crowns. 




Cavities in both upper and lower incisors which do not involve any more loss of substance than 
shown in No. 2 may be prepared as in No. 1. emphasizing the gingival and incisal point angles. 

Instrumentation. — If caries has progressed so that the enamel is under- 
mined, the chisel (No. 48 S, Fig. 131) is indicated for establishing cavity 
outlines. When the enamel is not undermined, a small round bur should 
br " - 1 to cut away the dentin immediately beneath the enamel, after 
which "' 1 "^.Y be cut away with chisels. After removing the 



184 



TECHNIQUE OF CAVITY PREPARATION 




Xos. 1 and 2 show labial and lingua] views of cavities like Xo. 1, Fig. 175. where the ' -incisal step" 
is employed. Xos. 3 and 4 show the lingual ' "step '' in similar cavities in such teeth as are too thin 
in the incisal third to warrant the employment of the incisal "step." 



Fig. 181 




The application of the "lingual step'' in an extreme case for a gold inlay. 



SMOOTH SURFACE CAVITIES 185 

softened dentin with small right and left spoon excavators, the retention 
form is made with small inverted cone burs, completing the gingival 
point angles with small hoe excavators and the incisal point angle with 
a small hatchet angle 28 (Fig. 125). 

The final enamel bevel is made with sharp chisels. Sandpaper disks 
and strips should be avoided because of the danger of rounding the 
enamel walls. In proximal cavities in the cuspids the preparation 

Fig. 182 




These teeth are reproduced as typical of most cavities where the marginal ridge has not been 
broken down, and show very clearly how form and contour influence the lateral spreading of caries 
on the surface of the enamel. 

shown in Fig. 178 may be employed. This is an application of the dove- 
tail mortise. In all this class of cavities the outline should be such as to 
produce the best artistic effect, and also to permit the easy and direct 
introduction of the filling material with the least possible separation. 

Cavities in the Proximal Surfaces of Incisors and Cuspids which Involve 
the Incisal Angle. — In these cavities the outline is indicated by the 
amount of tooth substance missing after all unsupported enamel and 
softened dentin has been removed. The retention in the gingival 



186 



TECHNIQUE OF CAVITY PREPARATION 



third is of the same form and shaped with the same instruments as in 
those cavities where the incisal angle is not involved. When the loss of 
tooth substance is not greater than that shown in No. 2, Fig. 179, the 
incisal retention may be made between the enamel plates (No. 1, Fig. 
179). When this loss is so great as to require a greater bulk of metal to 
restore contour than that within the cavity, as in No. 1, Fig. 175, we must 
secure some other kind of incisal retention. Figs. 175 and 180 show 
the two forms. The incisal step is employed in teeth which have been 



Fig. 183 




These molars illustrate the same points as those in Fig. 182. 

abraded or those that are thick in the incisal third. The lingual step is 
only used where the teeth are so thin in the incisal third as to preclude 
the use of the incisal step. In these cavities, as in those of the former 
class, the retention form is made with inverted cone burs, completing all 
angles with small hoe excavators, and the enamel margins finished with 
sharp chisels and trimmers. 

In preparing these cavities it is best to complete the preparation of the 
gingival third before making the incisal or lingual step (No. 2, Fig. 175). 



SMOOTH SURFACE CAVITIES 



187 



If gold inlays are to be inserted, the same cavity form is made when the 
incisal step is employed, except that all point angles are less pronounced. 
If the lingual retention is necessary, the cavity is modified, as in Fig. 181, 
and the inlay inserted from the lingual surface. 

Cavities in Proximal Surfaces of Bicuspids and Molars (Figs. 182 anc 183) . 
— As these cavities always involve the occlusal marginal ridge, except 
where the adjoining tooth is missmg, they come in the class of mortises 



Fig. 184 



Fig. 185 





The simple mortise of mechanics where two 
surfaces are involved. 



The application of the simple "dovetailed 
mortise" to a molar cavity where the buccal 
and lingual walls are sufficiently strong to 
warrant this style of preparation. 



Fig. 186 




In mechanics, this would be a "compound mortise. 



shown in Fig. 184. Where there is no decay on the occlusal surfaces, 
this simple mortise form may be employed, providing that the buccal 
and lingual walls are sufficiently strong to retain the filling against the 
stresses to which it is subjected (Fig. 185). When there is a cavity on 
the occlusal surface, or where caries has weakened the buccal or 
lingual wall, the auxiliary mortise or step in the occlusal surface must be 
made. Fig. 186 illustrates this double mortise, and Figs. 187, 188, and 189 



188 



TECHNIQUE OF CAVITY PREPARATION 



show its application to molar teeth. The preparation of this form of 
cavity is made by first opening the cavity with chisels (No. 2, Fig. 190). 



Fig. 187 



Fig. 188 




The application of the "compound mortise" 
or "step" to a molar cavity. 




A proximal view showing the application 
of the "compound mortise" to a cavity in a. 
molar. Note the supporting dentin between 
the cusps. 



Fig. 189 




The line on this section shows the planes and angles in a typical "step" cavity. 



The next step after removing the softened dentin is to make the gingival 
wall flat in both horizontal planes forming the seat. The axial wall 



SMOOTH SURFACE CAVITIES 



189 



should be parallel with the perpendicular axis of the tooth, which will 
result in a right angle with the gingival wall (Fig. 189). The buccal and 
lingual dentin walls should form right angles with the axial wall and the 
enamel walls bevelled as in Fig. 191. This is done with inverted cone 







Fig. 190 




1 




2 


3 




kHoIbh 




w 


^B 




. •. 








M, mm 


' 






flfthkk. .^H -' 





No. 1 shows a cavity in a hicuspid No. 2 is a cavity after unsupported enamel has been broken 
down and all softened dentin removed. No. 3 shows the modification necessary to produce the 
completed cavity. 




A step cavity in a bicuspid, which shows again how the dentin is preserved to support the cusps. 
Fig: 192 Fig. 193 Fig. 194 




Several applications of the "step" cavity to molars. In all of these the effort has been 
made to meet the requirements of a safe cavity outline for the enamel with the least sacrifice 
of dentin in securing retention form, 



190 



TECHNIQUE OF CAVITY PREPARATION 



or square end fissure burs, and chisels for the enamel wall, emphasizing 
the angles with hoe excavators. The step is formed in the same way 
and with the same instruments as a simple pit and fissure cavity. The 
preparation should be such as to permit the insertion of a cast inlay. If a 
welded gold filling is decided upon, it is only necessary to emphasize 



Fig. 195 




A section showing the 
planes and angles in an ex- 
tensive "step" cavity. 



An occlusal view of the cavities shown in Figs. 188, 192, 
193, and 194. These show that the form of the auxiliary 
cavity or "step" was determined by the sulcate grooves. 



Fig. 197 




A section of one of the teeth shown in Fig. 182, illustrating the necessity for the liberal cutting 
seen in some of the previous pictures. 



the point angles with inverted cone burs and hoe excavators. If amal- 
gam is to be used, the bevel of the enamel walls must be less, especially 
on the occlusal surface. The illustrations show the several types of this 
form (Figs. 192, 193, 194, 195, and 196). 

One important point is to retain all the dentin possible between the 
cusps. (See illustrations.) 



CHAPTER VIII 

EXCLUSION OF MOISTURE— EJECTION OF THE SALIVA- 
APPLICATION OF THE DAM IN SIMPLE CASES, AND 
IN SPECIAL CASES PRESENTING DIFFICULT COM- 
PLICATIONS—NAPKINS AND OTHER METHODS FOR 
SECURING DRYNESS 

By LOUIS JACK, D.D.S. 



Fig. 198 



The interference of the secretions of the mouth 
constitutes an obstacle to the treatment of the 
teeth. In some instances the flow is naturally 
excessive, and in all cases it is stimulated by the 
operative procedures. 

An excessive flow of saliva is uncomfortable to the 
patient; its accumulation also impedes the operation, 
and interferes with the view of parts by refracting 
the rays of light. 

During the preparation of accessible cavities, 
particularly those of the upper front teeth and the 
occlusal surfaces, the accumulation may be carried 
off by the use of a saliva 
ejector, a simple form of 
which is shown in Fig. 198, 
which form, or some modifi- 
cation of it, is used when a 
connection can be made with 
the water supply, and ordin- 
arily it is used in association 
with the fountain cuspidors. 
Another form, which is con- 
nected with a small reservoir 
of water, is shown in Fig. 199. 
Either of these forms has a 
further use for drawing off 
the saliva in connection with 
the employment of the rubber 
dam to lessen the discomfort 
of the patient. 



Fig. 199 




(191) 



192 EXCLUSION OF MOISTURE 



USE OF THE RUBBER DAM 



During the preparation of cavities on the proximal surfaces of the 
bicuspids and molars where it is essential to have unrestricted view 
and the exclusion of blood, the presence of which is inseparable from 
thorough preparation of the cervical margins, it is necessary to make use 
of the rubber dam. When used for this purpose the material generally 
becomes impaired by the action of the instruments in their free use 
at the cervix; but the economy of time and the essentials of thorough 
performance of this class of operations warrant the application in many 
cases during this portion of the treatment. 

When the case is ready for the filling process, a new piece of the dam 
should be prepared, and adjusted with great care to prevent the ingress 
of the least moisture. Without this appliance the greatest skill is power- 
less to secure sound results in large, difficult, or complicated cases. 
The introduction of this invention by the late Dr. Sanford C. Barnum 
has made it possible to secure sterility of the field of operation and to 
execute with gold, operations which previously were impossible; while 
not the least advantage resulting from its use is that the operator has 
free use of the left hand to assist the right. 

Quality of the Rubber. — The quality of the rubber greatly modifies 
the facility of its application. It should be of medium thickness and 
of light color, as it then absorbs less light. It should be freely exten- 
sible, and so elastic that when the thumb is forcibly pressed into it it 
returns to its normal form on the removal of the force. If it responds 
to this test it will not tear if fairly applied. 

The size and form of the piece should be such as to avoid encum- 
bering the face of the patient and to permit the lateral extension to be 
folded out of the way in such manner as to prevent obstruction of the 
view. The form generally best suited is a triangle, which form also 
permits of its most economical use. 

For the front teeth the piece should be moderately small; for the 
bicuspids and molars the size should be ample, and is best adapted 
when cut from strips about seven and a half inches in Width. 

The selected piece should have holes cut in it of such size as to corre- 
spond with the dimensions of the teeth over which it is to pass. When 
more than one hole is required, the holes should be at such distances 
apart as will present a sufficient amount of material to allow for the 
take-up in the application, so that the strait which passes between 
the teeth shall be sufficient to allow the edge to be carried upward to 
form a valve at the cervices of both teeth and not be under such strain 
as to interfere with the valvular action of the edges of the rubber. At 
the same time there should be no excess to hamper the view or interfere 
with the placement of the filling material, Ordinarily two or more 



USE OF THE RUBBER DAM 



193 



Fig. 200 



Fig. 202 




Fig. 201 




— 



a b d c 

Diagrammatic drawing: form of valve. 




teeth on each side of the tooth 
which is to be operated upon 
should be passed through the 
rubber dam to give greater 
security to its adjustment as 
well as convenience in opera- 
ting. 

Attention to the valvular ar- 
rangement of the dam at the 
cervix will avoid subsequent 
difficulty, and will prevent, in 
many instances, the infliction 
of pain in using ligatures ex- 
cept upon the tooth under 
treatment and the adjacent 
one. 

The diagrammatic appear- 
ance of this valve is shown by 
Fig. 200, and in perspective by 
Fig. 201, a, b, c, d. 

The holes in the rubber may be formed with a punch of suitable 
size, which should be forced upon the end of a close-grained piece of 
hard wood. They may be made with a little practice by drawing the 
13 



The Ainsworth punch. 



194 



EXCLUSION OF MOISTURE 



rubber over a round-ended instrument with some force, and pricking 
the rubber at a suitable point with a sharp knife, when a round section 
escapes. The difference in size of the holes is determined by the distance 
from the end of the instrument at which the puncture is made. The 
determination, however, of size and distance is not easily made in this 
manner. The best appliance for the purpose is the Ainsworth punch 
(Fig. 202), with which complete control of size and distance may be 
easily effected. 



Fig. 204 



Fig. 205 




For central incisors. 



For upper bicuspids and molars. For lower bicuspids and molars. 



Fig. 206 



The arrangement of the holes in the triangular piece should differ 
for each section of the mouth. 

Fig. 203 shows a piece for the central incisors. The figures represent 
inches. 

Fig. 204 shows the arrangement of holes for the upper bicuspids and 
molars. It will be observed that the line of holes is not parallel with 
the upper edge. 

Fig. 205 shows the arrangement for the lower bicuspids and molars. 
Here, too, the line of holes is not parallel with the edge, to allow for 

the difference in distance from the commis- 
sure of the lips to the anterior and posterior 
holes. 

Fig. 206 shows the arrangement when the 
lower incisors and canines are included. 
Here the line of the apertures is curved. 

By conforming to these arrangements of 

the openings in the rubber, and by extending 

the line in conformity with it, as well as by 

increasing the size of the piece, any number of holes may be made, to 

include any portion or all of the teeth of one-quarter of the denture 

when that may be required. 

The number of apertures in the rubber should be such as to give 
easy access to the operation and to permit the free entrance of light. 
For the anterior teeth five to six holes are necessary, and for the pos- 
terior teeth, from four to six, as may be needed to secure the above-stated 
objects. In general, at least two teeth anterior to the one operated 
upon, and when admissible, the one posterior, should be included. 




For lower front teeth. 



USE OF THE RUBBER DAM 195 

The Placement of the Dam. — When the teeth are not in firm contact, 
or when their attachments are flexible, the adjustment of the dam is 
simple. But when the teeth are rigid certain preliminary conditions 
should be secured. It has been pointed out (Chapter IV) that in the 
preparation of the teeth for a series of operations, they should be well 
cleaned of any deposits which may be upon them and be polished on 
their approximal surfaces. This makes easier the insertion and the 
application of the rubber. 

Generally, when the case under treatment is a proximal surface, 
the necessary preparatory separation makes easy the immediate open- 
ing of any interstices near the operation. In cases of extreme fixation 
of the teeth a piece of rubber dam placed for a day or so in a couple 
of the neighboring spaces makes it easy to pass the rubber through the 
margins of the interstices. The passage of a silver tape with a little 
benne oil or vaselin on it often answers as an equivalent means. In 
the front teeth a thin wedge inserted just above a tight point permits an 
easy entrance. 

The preliminary silking of the adjoining spaces, particularly if the 
silk be coated with vaselin or its equivalent, also facilitates the passage 
of the rubber, and for this purpose soaping the under surface of the 
rubber adjacent to the holes is recommended. 

At first the novice finds difficulty in making application of the dam, 
but practice cultivates facility. In general it is better to commence with 
the anterior hole and proceed posteriorly until all the intended teeth 
are included. Thus for the left lower teeth the rubber is taken with 
the index fingers applied to the upper surface, the other fingers to the 
under surface, and is grasped near the hole for the front bicuspid; the 
hole is extended; the edge of the rubber is inserted in the mesial inter- 
stice and is carried down to the gum. It is then drawn over the tooth 
and passed into the next interstice in the same manner. This method 
is pursued with each tooth until all are included. The passage of the 
rubber is facilitated by helping it downward by the insertion of floss 
silk, which is held taut, and with a firm and gently sliding movement 
the rubber is conveyed toward the cervix. 

When the most distant tooth is the lower third molar, it is generally 
best, when the cavity is on either side of the last interstice, to pass the 
jaws of a dam clamp through the posterior hole; the clamp is then made 
to grasp the tooth, the dam is conveyed to the gum by waxed floss silk, 
and the adjustment is then carried forward from tooth to tooth. The 
same procedure is sometimes applicable with short third molars in 
the upper denture, or in case any of the posterior teeth are so shaped 
as not to retain the rubber. 

WTien the rubber is adjusted over the teeth the purpose of the dam 
is effected by directing the edge of the dam under the free margin of 
the gum. This is done by passing a silk thread around the tooth, and 



196 EXCLUSION OF MOISTURE 

crossing the ends, when by a drawing movement of the thread it travels 
down the inclined surface of the cervix, carrying the dam with it, thus 
making a more secure formation of the valve. 

This method avoids the needless paining of the patient caused by 
pushing the threads against the gum with instruments. Whenever 
necessary for security the ligature should be tied. This should be 
done to the teeth on both sides of a proximal cavity. It is neces- 
sary here to place the cervical margin of the cavity in full view and to 
make certain the exclusion of moisture, which otherwise might pass the 
valve by capillary attraction. 

The ligature should usually be passed but once around the tooth and 
then be tied with a surgeon's knot, the place of the knot being on the 
outside. When there is much strain the thread may be passed twice 
around the tooth, but this should be avoided as being more painful and 
as increasing the bulk of the ligature. 

To prevent the rubber from displacement by the movement of the 
cheeks on the posterior teeth when they are long, if after drying the 
surface a little sandarac or dammar varnish is applied at the last inter- 
stice the rubber becomes fixed. 

In cavities extending above the cervix, w T hen a ligature cannot be 
placed above the cervical border of the cavity, other means have to be 
adopted to obstruct the entrance of fluids. Here the strait of rubber 
between the holes should be much wider than usual; the abundant fold 
may then be forced beyond this margin with a matrix, w T hen, by drying 
the parts and by the deft introduction of alcohol varnish and suitable 
wedges, dryness of the parts is attained. 

The Securement of the Dam from Displacement. — When the teeth 
are short from incomplete development, or when their form is tapering 
from the gum toward the occlusal aspect, there is always a tendency of 
the rubber to escape, and the contraction of the commissure of the lips 
tends to the displacement of the dam at the posterior teeth, the latter 
movement often being sufficient to overcome the friction of the ligatures. 
When these difficulties arise a clamp is required. 

Fig. 207 Fig. 208 





Dr. Southwick's clamps. Dr. Huey's clamps. 

The Clamp. — This is an instrument of much value not only as a 
means of securement of the rubber, but as an adjunct to prevent the 
rubber from obstructing the view. Clamps are more especially needed 



USE OF THE RUBBER DAM 



197 



to detain the rubber on the molars and are rarely required for the bicus- 
pids or the anterior teeth, since, if the foregoing directions are followed, 
the necessity for their use will but seldom be presented. 

Forms of Clamps. — For the molars various sizes and shapes of the 
" South wick" and of the "Huey wisdom- tooth clamp" are sufficient 
for general use. In addition to these, "Palmer's set of eight," after 
the sharp points of the jaws are rounded, will furnish the requisite 
variety. 

The Application of the Clamp. — The selected clamp is extended by 
the clamp forceps to enable it to pass over the molar. It is conveved 
to the middle portion of the tooth, when the inner beak should be 
brought against the tooth at the gum margin; then with this point as a 
fulcrum, the outer beak is carried to the cervix on the buccal surface. 
Much pain may be avoided in the employment of this appliance by 
deft and careful placement. Injury of the gum and needless pain has 

Fig. 209 




Dr. Delos Palmer's set of eight clamps. 



frequently been inflicted by careless use of force in the application of 
this appliance. Much of this may be avoided by the previous ligation 
of the tooth, which will prevent the tendency of the clamp to descend 
beneath the gum when the necks of the teeth are much inclined inward. 

When it is necessary to force the clamp against the soft tissues, the 
previous application of a solution of cocain will obtund the tissue and 
render the application bearable. 

The Arrangement of the Dam on the Face. — This concerns the con- 
venience of the operator and the comfort of the patient. To give easy 
access and permit the entrance of light, the rubber is drawn aside at 
each upper corner by dam holders. The simpler forms of these are 
sufficient and are more convenient than the more complicated ones when 
triangular pieces of rubber are employed. In addition a supporter, 
shown 'at Fig. 211, passes over the head and engages at each end 
with the holder. The comfort of the patient is secured by including a 



EXCLUSION OF MOISTURE 



napkin along with the rubber in the clasps of the holder. The excess of 
the rubber at each side should be taken up in a fold and secured to the 
napkin by dressing pins. The suspended part of the rubber is kept 
taut by pendant weights. 

The application and arrangement of the dam becomes, by practice, 
a very simple matter, and should not be the occasion of discomfort or 
pain to the patient. 



Fig. 210 



Fig. 211 






Design of Dr. Cogswell. 



A supporter. 



The Use of Napkins. — There are many instances of simple cases in 
accessible positions not of proximal surfaces, when the general flow 
of saliva can be kept under control by the saliva ejector, where it is not 
necessary to use a rubber dam. Also for children, when the teeth are 
too short to permit the correct application of the dam, it is necessary to 
find other means to control the moisture. Here the reliance is upon 
napkins, and with them much skill may be displayed by deft operators. 
For this purpose the napkin should not be over eight inches square. 
The manner of folding is to carry two adjacent edges to the diagonal 
of the napkin, and then fold again in like manner; by this plan the 
folds are held in place. 

To apply a napkin to the upper right side, the point is taken between 
the left index finger and the thumb, the broad end being held at the 
same time by the right hand. The lip near the right commissure is 
everted, the point is inserted here, and by the taut action of the left 
hand, the napkin is next laid between the gum and the lip. It is then 
carried backward until it reaches the duct of Steno, when the left 
index finger is applied to maintain the compression at this latter point. 
The free end of the napkin lies upon the lower lip. For the left side 
the action is the same by the reversal of the hands. 

For the lower teeth the application differs by commencing for each 



USE OF THE RUBBER DAM 



199 



side at the upper canine of that side. When the duct of Steno is reached, 
a fold is made to effect the compression of the orifice of the duct, then 
the napkin is laid between the cheek and the lower teeth, and kept in 
position by the left index finger, a mirror, or a check-holder. 

An important preliminary to the application of a napkin to these 
positions is that the saliva ejector be first placed in action and that the 
surfaces of the gum and cheek be wiped to dryness, to cause the napkin 
to cling to the surface. If the surfaces are covered with mucus and 
at the same time are wetted with saliva, the napkin easily becomes 
displaced. 



Fig. 212 



A 




Aseptic Napkins. — For simple procedures, such as dressings, making 
examinations, putting in temporary stoppings, and small occlusal fillings, 
the recently introduced aseptic napkins are very useful. They are 
folded into triangular shape. The evolution into this form is shown 
by Fig. 212. 



Fig. 213 



Fig. 214 









FZij 




KB 


Mk~' 10 


w*^ 






In the completed form these may be placed in any. convenient manner 
to assist in protecting many easy cases from the encroachment of saliva. 
Used in connection with absorbent and non-absorbent rolls they furnish 
much facility, and do not encumber the mouth or cause distress. Fig. 
213 shows the manner of applying the folded aseptic napkin, where 
it is held in place by an Ivory clamp. In this and similar cases a short 
piece of non-absorbent roll may be included with advantage at the part 
opposite the duct of Steno, which by the pressure will occlude this duct. 



200 EXCLUSION OF MOISTURE 

Similar means may be followed with the lower teeth by placing 
non-absorbent rolls as appears in Fig. 214. When in connection with an 
absorbent roll to occlude the parotid duct, uncomplicated occlusal cases 
are carried on with facility. Hence it will appear the field of work may 
be upon any of the teeth within the limits of the rolls. 

Nausea. — The contact of the rubber dam with the tongue and the con- 
tiguous parts, the presence of napkins, and the touch of the fingers to the 
oral surfaces frequently excite nausea. With some persons this kind of 
distress is extreme and produces simulation of faintness and nervousness. 
This condition may generally be relieved by the use of aqua camphora, 
a few drams being used as a gargle to the mouth and throat. When 
indications of faintness appear a dram may be swallowed with immediate 
benefit. 

In case excessive nausea is occasioned by the contact of the appli- 
ances with the tongue or palate, these surfaces may be painted with 
tincture of camphor. Spasmodic coughing, not infrequent with nervous 
persons, yields to the same treatment. Camphor appears to relieve in 
these instances by its antispasmodic power, and it is stated to have also 
a specific action upon the eighth pair of nerves. 

Nervousness coming on during any of the operations upon the teeth 
may as easily and in the same manner be avoided. It will be observed 
that in neither of these conditions are the first signs of approaching 
syncope apparent, viz., sighing respiration, pallor, and clammy perspira- 
tion of the face. 

A condition somewhat simulating approaching syncope, sometimes 
appears in connection with the use of the rubber dam, due to partially 
suspended respiration, which is caused not so much by the obstruction 
of the mouth as by the unpleasant sensations occasioned by the appli- 
cation and presence of the dam. This may at once be overcome by 
requesting the patient to breathe deeply through the nose. 



CHAPTER IX 

THE OPERATION OF FILLING CAVITIES WITH METALLIC 
FOILS AND THEIR SEVERAL MODIFICATIONS 

By EDWIN T. DARBY, D.D.S., M.D. 

In the selection of a filling material the operator should consider the 
character of the secretions of the oral cavity, the position of the tooth 
to be filled, the extent of the diseased area, the physical structure of the 
tooth, and the strength of the cavity walls. A filling material must 
possess certain inherent qualifications, the most important of which are 
adaptability, indestructibility, non-conductivity, hardness, absence of 
shrinkage, harmony of color, and ease of manipulation. All of these 
are not to be realized in any one material, and yet some of the more 
important are to be found in a single metal or in a combination of metals. 

Lead, formerly used as a tooth-filling material, possesses the quality 
of softness and is easy of adaptation, but is readily oxidized when 
exposed to the air or the secretions of the mouth. Likewise tin pos- 
sesses characteristics, such, for instance, as ductility and softness, low 
conducting power, and the ease with which it may be manipulated, 
which place it in the front rank as a preservative of carious teeth, but 
it is inharmonious in color, and its very softness, which is so desirable 
in manipulation, is an obstacle to its use upon surfaces where there 
is much attrition. The zinc phosphates, which are composed of zinc 
oxid and phosphoric acid in solution, form a combination which at 
first attracted the favorable attention of the dental surgeon as possible 
substitutes for metallic foil fillings. They possess, owing to their plas- 
ticity, ease of manipulation, harmony of color, comparative non-con- 
ductivity, and absence of shrinkage, many desirable qualities, but are 
lacking in one essential qualification, namely, indestructibility. 

The silicate cements, which are attracting so much attention at the 
present time, have some superior qualities over the zinc phosphate 
cement in that they have more lasting qualities, but they are brittle and 
the edge strength is poor. 

GOLD 

Gold, which has been used for about a century, has fulfilled in a more 
marked degree than any other material or combination of materials the 
requirements sought for in a filling for carious teeth. It has one or two 

(201) 



202 THE OPERATION OF FILLING CAVITIES 

objectionable features, such as high conductivity of heat and electricity, 
and inharmonious color. 

Too much stress cannot be laid upon the question of its purity if the 
best results are to be obtained from its use. While it is claimed by 
manufacturers of dental gold foil that their products are absolutely free 
from alloy, it is nevertheless true that but few specimens of dental foil 
show a fineness above 999. If this standard were always attained the 
operator would have little cause for complaint. So small a percentage 
of alloy as 1 in 1000 would not materially affect the working qualities 
of the product, but when this is increased to 4 or 6 parts per 1000 it 
manifests itself by harshness and intractability under the instrument. 

Great care should be exercised in the preparation of the foil, since 
so much depends upon its purity and cleanliness. For a detailed 
description of the process of manufacture, from ingot to the beaten 
and annealed foil, the reader is referred to an article by a practical 
foilmaker. 1 

In former times the dental surgeon was restricted to one form 
of gold for filling. This was foil ranging in thickness from 4 to 10 
grains to the leaf, but as the requirements of the operator broadened 
the art of manufacture increased, and new preparations were offered, 
until today the most fastidious can find such as will please his fancy: 
foils ranging in weight from 4 to 120 grains to the leaf; cylinders of 
various sizes and composed of non-cohesive and semi-cohesive foil; 
cohesive blocks prepared for use; rolled gold, varying in thickness from 
No. 30 to 120, and crystal gold possessing great cohesive properties. 
These are the more important forms in which gold is offered the operator 
at the present time. 

Before entering upon a description of the classes of cases where each 
of these seems best adapted, it may be well to describe somewhat in 
detail the peculiar qualities which each form of gold presents when 
subjected to clinical use. 

Soft or Non-cohesive Foil. — Prior to 1854, when Dr. Robert Arthur 
discovered and promulgated the desirability of cohesive foil in certain 
cases, the operator used gold which possessed very low cohesive proper- 
ties. Used as it then was, in the form of large rope, tape, or as cylinders, 
the property of cohesion would have been a serious objection, since there 
would be constant danger of the mass clogging and bridging in the 
cavity, and the cause of many unfilled places along the cavity walls. 

The terms soft and hard, when used to designate the kind of gold, are 
misleading, since all gold foil prepared from pure gold or gold that is 
nearly pure possesses great softness under the instrument. The distin- 
guishing characteristics between the two kinds of gold are the inability 
to make a certain kind of foil cohesive when exposed to a reasonable 

1 American System of Dentistry, vol. iii, p. 839. 



GOLD 203 

degree of heat, and the ability to render another make of equal purity 
cohesive by the application of a similar degree of heat. It has been 
claimed by some manufacturers of dental gold foils that they are able 
to produce from the same ingot samples of non-cohesive, semi-cohesive, 
and extra-cohesive gold, attaining these physical properties of the mate- 
rial without alloying with other metals. This has led to the belief 
that, since absolutely pure gold possesses inherent cohesive properties, 
some metallic salt or other foreign substance has been deposited upon 
the surface of the leaf of non-cohesive foil which has the power of pre- 
venting the union of the surfaces of the foil when contact is sought. 
It has been surmised that a thin film of iron has been deposited upon 
the surfaces of the leaf of non-cohesive foil, for the reason that if a 
leaf of such foil be melted into a globule, it presents a reddish-brown 
appearance, which is not true of the leaf of cohesive foil when melted 
as above. 

Much of the so-called non-cohesive foil offered for sale is not, strictly 
speaking, of this variety, as the application of moderate heat will render 
it quite cohesive. It possesses the softness peculiar to pure gold foil, 
but it should not be classed with the variety which does not weld with 
other particles of the same metal except when subjected to great heat. 

It has been claimed by some that non-cohesive foil has no place in 
dental practice — that any tooth which can be filled with gold may be 
filled with cohesive foil. This statement may be true in the main, but 
it is also true that many teeth having strong cavity walls can be just as 
well filled where a large portion of the filling is made with non-cohesive 
foil, and with a great saving of time. Adaptation, not hardness, con- 
stitutes the saving quality in cavity filling. 

As most non-cohesive foil is prepared in the form of sheets and is 
placed in books containing one-eighth of an ounce, the operator is com- 
pelled to prepare it in some form suitable for introduction to the cavity. 
The size and shape of the cavity will be some guide as to the best method 
of preparing the gold. The narrow tape, the mat, the tightly rolled 
cylinder, and the roll or rope are the forms best adapted for the use of 
non-cohesive gold foil. 

The tape is best made by taking one-half or one-third of a leaf of 
No. 4 or No. 5 foil, laying it upon a table napkin of medium size folded 
square as it comes from the laundry; the napkin is then taken in the 
palm of the left hand, and the foil spatula is placed in the middle of 
the piece of foil; the hand is then closed tightly, thus folding the 
napkin, likewise the foil, upon the sides of the spatula. This process 
is repeated until the tape is one-eighth or one-sixteenth inch in width 
(Fig. 215). 

If mats are required, the foil may be folded twice or three times and 
then folded lengthwise upon itself until mats of any thickness are pro- 
duced, as shown in Fig. 216. 



204 



THE OPERATION OF FILLING CAVITIES 



When non-cohesive cylinders are desired, it is better for the operator 
to make them rather than depend upon the ready-made ones as prepared 
by the manufacturer, since these are usually loosely rolled and more or 
less cohesive. The tape is quickly made into the cylinder by rolling it 
upon a five-sided broach to the desired size. The depth of the cavity 
is a guide to the width of the tape, and the width of the tape determines 



Fig. 215 



Fig. 216 







Tapes of gold foil. 



Mats of gold foil. 



the length of the cylinder. These should be somewhat longer than the 
depth of the cavity. The manner of introducing and condensing will 
be described later when special cases are under consideration. 

The roll, or "rope," as it was formerly called, is made in the following 
way: A leaf or half leaf or a third of a leaf of foil is rolled between the 
thumb and finger until a roll of moderate density is obtained. As foil 
is contaminated by contact with the moisture and surface impurities of 
the hands, it is better to avoid such contact as much as possible. This 



Fig. 217 




Devices for rolling gold foil. 



can be completely attained by rolling it upon the little device shown in 
Fig. 217. Any operator can make one of these by taking two pieces of 
thin board, such, for instance, as the lid of a cigar box, and fastening 
to the two pieces with glue a piece of white kid about eight inches in 
length, and in width equal to the sheet of foil. Two little drawer 
knobs of ebony or other hard wood should be inserted into the centre 



GOLD 205 

of each of the pieces of board. These act the part of handles for 
holding the appliance. The gold is first placed upon the kid strip 
between the lower edges of the covered boards, and by bringing the 
two surfaces of the kid in contact and rubbing them together with a 
to-and-fro motion the foil is rolled into a roughly made cylinder. The 
cylinder is then transferred to the board and further rolled until it is 
reduced to the desired diameter. The undressed surface of the kid 
should be the one upon which the gold is rolled. Ropes thus made 
may be cut in lengths to suit the size of the cavity to be filled, and, as 
gold thus prepared has great softness and ease of adaptation, it may 
be inserted in quite large pieces if plenty of condensing force be applied 
to it. 

Cohesive Gold Foil. — All gold which has been refined by any of the 
ordinary methods and is in a pure state may be said to be cohesive. 
Nor is absolute freedom from alloy an absolute necessity. It has been 
shown that softness is dependent upon purity, but a foil may contain 
quite a percentage of silver, copper, palladium, or zinc, and yet its 
cohesion may not be impaired. It may also be alloyed or combined 
with platinum and not lose its cohesive properties. It is, however, 
desirable that cohesive gold be pure, since the smallest peicentage of 
alloy destroys its softness. 

When two sheets or laminae of freshly annealed foil are brought into 
contact and slight pressure is applied, they form a permanent union and 
are practically inseparable. It is this property in gold to which the 
term cohesive has been applied. But this property is soon lost by the 
occlusion of gases or impurities of any kind which may be deposited 
upon the surface of the gold. 1 

Experiments have demonstrated the fact that if the gold be sub- 
jected to the fumes of ammonia, hydrogen, hydrogen carbid, hydrogen 
phosphid, or sulphurous acid gas, its cohesive property is quickly 
destroyed, but this property may be restored by heat, except in the case 
of sulphur or phosphorous fumes. Hence the importance of excluding 
the gold as much as possible from the atmosphere, especially during the 
winter months, when gases arising from the combustion of coal are most 
liable to be present in the operating-room. 

Dr. Black has shown that ammoniacal gas has the power to prevent 
the deleterious influence of other gases, and recommends that the foil 
be subjected to the influence of carbonate of ammonia by keeping it in 
a drawer with a bottle of that salt. 

The advantages of cohesive foil cannot be overestimated. With its 
introduction, in 1855, began a new era in the possibilities of saving 
carious teeth. Operations which were deemed impossible by the use of 
non-cohesive foil were made comparatively easy by the intelligent use 

1 G. V. Black, Dental Cosmos, vol. xvii, p, 138. 



206 THE OPERATION OF FILLING CAVITIES 

of cohesive foil. The restoration of broken-down or badly decayed 
teeth became the common practice in the hands of the skilful, and 
modern methods of practice, coupled with intelligent use of this form of 
gold, have made it possible for the operator of modern times to do that 
which the earlier practitioner deemed impossible. 

The beginner, however, must not lose sight of the fact that cohesive 
foil cannot be worked after the same methods as non-cohesive foil. To 
use cohesive foil in the form of mats or cylinders or in tightly rolled 
ropes would mean inevitable failure in adaptation. The very property 
which renders it valuable in the restoration of broken-down teeth and in 
surfacing is the one which would condemn it if used carelessly in the 
interior of inaccessible cavities. Non-cohesive gold may be introduced 
into a well-shaped cavity in large masses, and because of its softness 
and ease of adaptation may be made to touch all points of the cavity 
walls if persistent pressure be applied. On the contrary, cohesive foil 
should be introduced in small pieces, the first of which should be well 
anchored in a retaining pit or groove and each subsequent piece 
welded thereto. 

There are several modes of preparing the beaten cohesive gold foil 
for the cavity, and good results are obtained by either of the following 
methods : 

A loosely rolled rope made of a quarter sheet of No. 4 or 5 foil may 
be cut into lengths varying from one-eighth to one inch, and after 
annealing, carried to the cavity upon the point of the plugging instru- 
ment. Or a leaf may be folded with a spatula four times, making a 
broad ribbon, which may be cut either lengthwise or crosswise of 
the ribbon in pieces one-sixteenth or one-eighth of an inch in width 
(Fig. 218). This is a very convenient manner of working cohesive gold. 
Or the heavier foil up to No. 20 or No. 30 in thickness may be cut in 
strips of a single thickness and of the widths above indicated, and after 
annealing may be packed into the cavity — the essential idea being ever 
kept in mind, that but a small quantity of the gold shall be under the 
instrument at a given time. Cohesive gold which has been rolled instead 
of beaten to the desired thickness is much prized by some. It has been 
asserted that a greater softness is obtained when gold has been thus 
prepared. Such gold should not be more than No. 20 or No. 30 in 
thickness to insure the best results. It should be cut into narrow strips, 
and, after annealing, be folded back and forth as rapidly only as each 
previous fold has been well condensed. Good results are only attainable 
if each lamina be thoroughly welded. 

The loosely rolled cylinders and blocks which are prepared by some 
dealers and offered as cohesive gold are usually but slightly cohesive, 
and if used in this form, without re-annealing, may be packed in the 
interior of cavities without danger of clogging; but if freshly annealed 
they are contraindicated, since there is more or less danger of imperfect 



GOLD 



207 



union of all particles of the gold. It is questionable whether the larger 
sizes are admissible when the filling extends beyond the cavity walls, 
and great solidity is an essential factor. 

Crystal Gold. — This form of gold was introduced by Mr. A. J. Watts 
in 1853, and as prepared at the present time is one of the best prepara- 
tions of cohesive gold. When first brought out the method of manu- 
facture was faulty, since it was difficult or impossible to rid the spongy 
mass of nitric acid, which was used in its preparation, but since Mr. 
Watts adopted electrolysis instead of chemical precipitation the objec- 
tionable features no longer exist. Gold thus prepared manifests great 
cohesive properties, and when used with care, as beautiful operations 
can be made with this gold as with any form of cohesive foil. The 



Fig. 218 






H 



Ribbons and strips 



operator should not lose sight of the fact that the gold is to be introduced 
into the cavity in small quantities. Should failure attend its use, it 
would doubtless be from the attempt to introduce it too rapidly. Gold 
of this variety comes in bricks and strips containing one-eighth of an 
ounce each, and is either torn apart in irregular-shaped pieces or cut by 
means of a razor into small cubes. This gold should be excluded as 
much as possible from the atmosphere, and when used should be well 
annealed, although when recently made it is quite cohesive. 

Moss fiber gold is another form of crystal gold, and differs from the 
variety previously described in that the crystals seem larger, and the 
mass is not so compact. It may be used wherever a crystal gold is 
indicated. 



208 THE OPERATION OF FILLING CAVITIES 

Gold and Platinum. — This form of gold has found much favor with 
many practitioners for the restoration of incisal edges, or where for any 
reason great hardness of surface is desired. 

An ingot or bar of pure gold and one of platinum are "sweated'' 
together and then rolled to the desired thinness, usually about that of 
No. 20 or No. 30 foil. It is then cut into narrow strips, freshly annealed, 
and used after the same manner as heavy foil. The commingling of 
the platinum with the gold gives the filling a tint more nearly the shade 
of the tooth, and for this reason it is much used upon labial surfaces and 
in mouths where the teeth are much exposed. 

Gold thus combined with platinum is much more rigid than gold 
alone, and is contraindicated for making the bulk of most fillings. The 
best results are obtained from it when the mallet is used for its 
condensation throughout. 



ANNEALING GOLD 

After the manufacturer has reduced the gold to the desired thinness 
by beating, his last act before booking it is to heat it; this is termed 
annealing. Gold foil which has been recently made and excluded" from 
the atmosphere or certain gases, as previously mentioned, may present 
sufficient cohesive properties to weld satisfactorily; but this property is 
soon lost, and re-heating becomes necessary if it is desirable to get union 
of the various layers. 

Most operators make use of an alcohol flame for annealing gold; 
others a small Bunsen gas burner. Some hold the piece of gold to be 
annealed in the direct flame or a little above it; others place the gold 
upon a tray of Russia iron, mica, or platinum, and hold this in the flame 
of the lamp or gas jet. This latter method is safest, since there are apt 
to be impurities in the flame dependent upon a charred wick, a particle 
of phosphorus dropping into the wick from the burning match, or, in 
the case of the gas jet, imperfect combustion, which might give either 
carbon or sulphur deposits upon the surface of the gold. All or any 
of these accidents would impair the working qualities of the gold. 

The most satisfactory method of annealing gold is by the use of the 
electric annealing tray. Such a device has been invented by Dr. L. E. 
Custer, and is shown in Fig. 219. By this method the gold may be 
heated to any desired degree and with a uniformity not easily attained 
by the methods generally used. The working qualities of foil, whether 
non-cohesive or cohesive, are greatly enhanced by the application of 
heat at the time of using. Gold that is absolutely non-cohesive is made 
tougher by annealing and yet its softness is not impaired, while cohesive 
gold may be made either slightly or decidedly cohesive according as 
much or little heat may be applied to it. It is the practice of many 



IXTRODUCTION OF GOLD 209 

operators to use the gold but slightly cohesive when filling cavities sur- 
rounded by strong walls, and the gold known as semi-cohesive, in the 
form of loosely rolled cylinders, is much used. As the filling approaches 
completion the cylinders are heated and additional cohesive property 
imparted to them. But when the object is the restoration of contour or 
building-up of teeth which have been broken, the gold should be heated 
but little short of redness in order that the greatest cohesive property 
may be realized. 

Fig. 219 




Custer's electric annealing tray. 



INTRODUCTION OF GOLD, AND THE MANNER OF ADAPTING IT 
TO THE WALLS OF THE CAVITY 

It has been shown in Chapter VII that few cavities are of proper 
shape for retaining the filling when the decay alone has been removed. 
Most cavities require to be given a retentive shape so that the filling 
shall not be dislodged during its introduction or bv mastication or 
otherwise after its completion. In former times, when the operator was 
restricted to one form of gold, and that the non-cohesive variety, he was 
compelled to prepare his cavities accordingly; but at the present time, 
when the variety is almost endless, he can shape his cavity with a view 
to conserving tooth structure, and when he has given it the desired shape 
he can select, from the many, a special form of gold that will meet his 
requirements. 

There are certain principles involved in the packing of gold which must 
be borne in mind, and the operator should study these before introducing 
his filling. The first of these is the application of force, and the direction 
and relation of that force to the object to be attained. If a given cavity 
is to be filled with non-cohesive gold, the operator must take into consid- 
eration the strength of the cavity walls, and must determine whether by 
the wedging process which he will exercise in the effort to adapt the 
gold to the walls of the cavity he will run the risk of breaking them. 

Xon-cohesive gold is usually introduced by what is known as hand 
14 



210 THE OPERATION OF FILLING CAVITIES 

pressure. Each layer of gold is carried to the floor and the walls of 
the cavity by a process of wedging, and the mechanical arrangement of 
each piece of gold should be such that no portion of the gold can escape 
when the filling is completed. It will be shown later on, when con- 
sidering the various types of cavities to be filled, that in small cavities 
of simple shape the gold prepared in the form of tape is best suited, 
whereas in compound cavities or those of greater size the gold may be 
introduced in the form of compact cylinders or blocks. 

When it is desirable to use a combination of non-cohesive and cohesive 
gold, the former is generally introduced first and the cohesive is incor- 
porated with it by driving or forcing layers of cohesive into the non- 
cohesive. This is best effected by using single layers of heavy foil or 
rolled gold of a thickness equal to 20, 30, or 40 grains to the leaf. If 
the filling is to be made of but one kind of gold and that the cohesive 
variety, both hand pressure and percussion by means of the mallet 
may advantageously be employed. The operator who has learned to 
combine the two forms of gold and is not restricted to either method 
of packing is best qualified for the requirements which are presented in 
general practice. Perfect adaptation to the walls may be effected by 
either method, but greater celerity and the attainment of equal excel- 
lence may be reached by combining the two. 

Plugging Instruments. — In the selection of instruments for packing 
gold the operator should have a sufficient number to meet his every 
need. They should be of such a variety of patterns that every part of 
every cavity, however remote, can be reached with ease. It is a mis- 
taken notion that a large number of instruments (if well selected) is 
confusing. The operator should study his instruments and know their 
uses as thoroughly as he knows the letters of the alphabet, and if this 
be done and they be arranged in an orderly manner in his case, the con- 
fusion will be manifest in their absence, not in the possession of them. 

For packing non-cohesive foil none are better adapted than the set 
shown in Fig. 220, made from patterns furnished by Dr. B. J. Bing. 
This set should be supplemented by a small and a medium-sized foot- 
shaped condenser (Fig. 221) for packing cylinders, mats, or blocks 
against the gingival wall. 

The handles of instruments used for packing non-cohesive foil should 
be of such size that they can be grasped firmly in the hand. When made 
of wood they are light in weight and agreeable to touch. Plugging 
instruments should have as few curves and angles as is consistent with 
the ability to reach all points in the cavity. As these are multiplied, 
direct force is sacrificed. The point of the instrument should be as 
nearly as possible in a line with the shaft. Deviations from this rule 
are sometimes necessary in order to reach all points in the cavity. Most 
plugging instruments have serrated points and are used for all forms of 
gold. As a rule, these serrations should be shallow, and when cohesive 



INTRODUCTION OF GOLD 



211 



gold is employed they should be only sufficient to prevent slipping, 
as gold that is quite cohesive packs as readily with smooth points as 
with rough ones. 

Fig. 220 




8 9 10 



¥\ii\ 



1 I 



* if nil 



n 



12 



13 



14 15 16 17 

Dr. Bing's set of pluggers. 




Fig. 221 



Y 



It is not definitely known when packing gold 
by percussion was first suggested, but the idea is 
quite generally accorded to Dr. E. Merrit, of 
Pittsburg, who as early as 1838 used the hand 
mallet for condensing the surface of fillings 
which had been introduced by hand pressure. 
The first mallets used were of light weight and 
were made of wood or ivory. As the method 
became more general, heavier mallets were em- 
ployed, and those made of lead, tin, various al- 
loys, and steel found much favor. Before the intro- 
duction of rubber dams for excluding moisture 
one hand of the operator was employed in holding the napkin, and it 
became necessary to have an assistant at hand to do the malleting. 
This led ingenious minds to discover some means of percussion besides 
the hand mallet, and several spring instruments known as automatic 
pluggers were introduced. The Snow and Lewis, the Foote, and the 



Foot-shaped con - 
densers. 



212 THE OPERATION OF FILLING CAVITIES 

Salmon found greatest favor, and all of them were good of 
their kind. Fig. 222 shows the Snow and Lewis automatic mallet 
as made at the present time. When pressure is applied to the 
point of the instrument a spring is liberated which throws a plunger 
forward with great force, which is expended upon the gold beneath the 
point. The impacting quality of this blow is not excelled by any of 
the mechanical devices in use. It is so constructed that a light or a 
heavy blow can be given at will. The operator will do well to adjust 
the instrument for light blows when using it in close proximity to frail 
or delicate walls, as there is more or less danger of fracturing them. 

Instruments of this class are not well adapted to packing gold in 
the posterior teeth of the lower jaw, as the blow is delivered at a more 
or less obtuse angle, and unless care be exercised when the operation is 
nearing completion the plugger point will slip from the surface of the 
filling and wound the soft tissues. 

Another instrument of this type, devised by Dr. Frank Abbott 
(Fig. 223), has a socket at either end of the hand-piece, the one giving 
a pushing and the other a pulling blow. The latter is serviceable for 
condensing gold upon distal surfaces. 

The electric mallet is one of the most ingenious devices employed 
in dentistry. The first practical application of electromagnetic force 
for dental malleting Was made by the late Dr. W. G. A. Bonwill. Its 
latest development is shown in Fig. 224. This instrument has found 
great favor among dentists for packing cohesive gold. Its blows are 
delivered with great rapidity and with such force that great solidity is 
attainable. A pair of electromagnets transforms the electric current 
into electromagnetic force, which is transmitted to the hammer. The 
electric current is furnished by a Bunsen or Partz battery, or the 
controlled current from a dynamo or storage battery can be used as 
the motive power. The direct dynamo current of 110 volts can be so 
modified by the use of a rheostat that its use may be employed, and the 
trouble incident to keeping a battery charged avoided. In the hands 
of a skilful operator there could be nothing better for packing cohesive 
gold. The best results are obtained by its use when the gold is prepared 
in thin laminae or where a single thickness of heavy foil or rolled gold is 
employed. 

Considerable experience is necessary to enable the operator to use this 
instrument with satisfaction to himself and his patient. If the plugger 
point be pressed hard against the filling, the blows, which are delivered 
with great rapidity and force, become painful and distressing and there 
is also danger of chipping the cavity walls. The better plan is to hold 
the point slightly away from the surface of the filling and allow the 
momentum which is given the instrument by the falling armature to 
complete the union of the various pieces of gold. 



Fig. 222 



Fig. 223 



Fig. 224 




Snow and Lewis auto- The Abbott mallet, 
matic mallet. 



S. S. White electric mallet "No. 2." 

Founded on the ' 'Bonwill." (213) 



214 



THE OPERATION OF FILLING CAVITIES 



Fig. 225 



The engine mallet (Fig. 225), known as the "Bonwill mechanical 
mallet," should be used upon a cord engine only. Much of the dis- 
favor which has attended its use has been owing to the fact that it has 

been applied to cable en- 
gines, and for which it is 
not in any way adapted. 
The instrument shown in 
the illustration embodies 
many improvements in 
construction which have 
been suggested by various 
operators, and a point of 
relative perfection has been 
reached where are com- 
bined great efficiency with 
compactness and lightness 
in handling. It will be 
seen by the illustration that 
the essential feature of this 
instrument is a revolving 
wheel, having inserted in 
its periphery a hollow 
cylindrical steel roller. 
This constitutes the ham- 
mer. It gives an "elastic" 
not a "dead" blow, as it 
is held to its position by 
a stiff steel spring. The 
roller revolves slightly in 
its socket at each contact 
with the plunger. When 
the engine is run at ordi- 
nary speed the wheel re- 
volves with great velocity, 
delivering upon the head 
of the plunger as many as 
fifteen blows per second. 
The force of the blow 
can be modified at will 
by an extremely simple 
contrivance, as follows : 
The interdigitations seen 
around the upper end of 
the sleeve are held to- 
Engine mallet. gether by means of a 




INTRODUCTION OF GOLD 



215 



spring attached to the sleeve. Pulling the sleeve away from the head 
against the spring, and revolving it to the right or left, raises or lowers 
the head of the plunger. Upon releasing the sleeve the spring at once, 
throws it back to engage with the head, and the blow is heavier or 
lighter, according to the direction in which the sleeve has been revolved. 
The impacting power of the blow from this is great, and in the hands 
of an experienced operator a large quantity of gold can be condensed 
in a short space of time. When cohesive gold foil is employed smooth 




Fig. 226 

-Ess-mo! — Emura 




s.Y.y.fA'.v.x 






Webb's set. 



I? 



1 M 

Chappell's set. 



oval points may be used with most satisfactory results. The point 
should not be pressed hard against the filling, but a skimming or smooth- 
ing motion given to the instrument. The surface of the filling when 
thus packed has a polished or planished appearance as if done with a 
hand burnisher. Such fillings are usually of great density. 

There are other mechanical mallets intended for use on the engine 
which have what is known as a "cam" movement. They are not, 
strictly speaking, mallets, for the instrument is pushed rather than 



216 



THE OPERATION OF FILLING CAVITIES 

Fir,. 227 



© © • © © • 




2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 



€ss n;;H3 Cn r»»^ 



dffil COOI GSSD ES3 Es!!! (0119 <nl3 on 




18 19 20 21 



driven forward by an eccentric. The Buckingham and the 
Holmes mallets belong to this class. They have not the same 
steadiness of motion as the ones previously described, and for 
this reason, among others, have not been in general use. 

In the selection of plugger points for power mallets the operator 
will do well to confine himself to those having more than one 
row of serrations and those which are smooth-faced. The 
serrations, if any, should be extremely shallow, and the corners 
of the instrument slightly rounded. Those of the foot-shaped 
variety are admirably adapted to power mallets, and as there 
is a great variety of patterns and sizes he will have little diffi- 
culty in meeting his every wish in this particular. A few points 
selected from the Webb, the Varney, and the Chappell sets will 
fill all requirements. The accompanying cut (Fig. 226) shows 
a good working set which has been selected from the three 
mentioned. The handles of these instruments are too small to 
be grasped firmly in the hand, nor are they well adapted for use 
with the hand mallet. The accompanying set shown in Fig. 
227 comprises instruments which may be used as hand pluggers 
or in conjunction with the hand mallet. Many of them are in- 
tended for hand pressure alone. It is not necessary that the 
beginner purchase the entire lot at the outset, but it is thought 
that with this combination his every need will be filled. 







FILLINGS BY CLASSES 217 



FILLINGS BY CLASSES 

Class A: Smooth Surface Cavities, Cavities in the Gingival Third of 
Labial, Buccal, and Lingual Surfaces of the Teeth. — Most cavities upon the 
smooth surfaces of the teeth are simple in form in that they have four 
walls surrounding them. 

There is some difficulty in filling such cavities if the gingival wall of 
the cavity is above the gum line, and a fold of its membrane extends 
into the cavity. In such an event it is better to press the gum away 
with gutta-percha or some similar substance and post- 
pone the filling with gold until absorption shall have 
taken place, which in most instances will require only 
a few days, or at most not more than a week or two. 
If the overhanging gum tissue is not too great it may 
be cut away with a sharp bistoury, and the operation 
completed at the same sitting. However, in most 
instances the rubber dam can be applied, and by 
means of a Woodward clamp (Fig. 228), held in posi- Woodward damp, 
tion throughout the operation of inserting the filling. 

If the clamp is not at hand, the same thing may be accomplished, but 
with a little more effort, by using a straight instrument, the end of which 
has been made round and sharp by honing it on an Arkansas oil stone. 
The dam is then raised well above the gingival wall of the cavity and the 
point of the instrument pressed well into the cementum and held with 
the left hand throughout the filling of the cavity. 

No effort should be made to force a ligature above the gingival border 
of such cavities, for such a procedure would not only wound the gum 
where it dips low into the interproximal spaces, but would be liable to 
set up an irritation in the gingivae and possibly in the peridental mem- 
brane, and would also, in the nature of things, be attended with failure. 

It is always well when filling such cavities to include in the rubber dam 
at least one or more teeth on either side of the one being operated upon. 

Cavities of this order are usually shallow and need no resistance form, 
and what little retention form they require is to be found in the point 
angles. 

If cohesive gold is used for starting the filling (and it is usually indi- 
cated), the point angles at the axio-mesial and axio-distal walls should 
be deepened into a convenience or starting point and the first piece of 
gold thoroughly fixed therein, after which the remainder of the filling 
may be added without danger of rocking or rolling in the cavity. The 
operator should learn early that where a filling is to be made of cohesive 
gold alone, his first piece must be securely anchored; otherwise he will 
be building upon an unstable foundation and his operation will prove a 
failure. If, on the other hand, it is thought best to start the filling with 



218 THE OPERATION OF FILLING CAVITIES 

gold that is non-cohesive, or with soft mats, or cylinders, known as 
semi-cohesive, he may lay a foundation upon the axial wall, forcing the 
gold well into the point angles, and, after partially condensing, work 
some cohesive gold into the mass, completing the filling with gold that 
has been freshly annealed and made quite cohesive. These cavities are 
so exceedingly simple when the rubber is held securely above the gin- 
gival wall of the cavity that failure to make a good operation would be 
rare. Nevertheless, the operator must not overlook the importance of 
packing his gold in the direction of each of the four walls, that it may be 
thoroughly bound into the cavity by these walls. Great care should be 
exercised not to batter or injure the cavo-surface angle. A sharp, well- 
defined border adds materially to the artistic appearance of such fillings. 
As gold fillings upon labial surfaces of the teeth are usually conspicuous, 
it is often well to fill such cavities with platinous gold, because the tint 
of the two metals in combination is more nearly the shade of the tooth; 
especially is this true in teeth of yellowish hue. 

While decay upon the labial surface of the incisors and cuspids does 
not often extend over the labio-mesial or labio-distal angle of the tooth, 
it does sometimes happen that the cavities upon the proximal surface 
of the teeth extend so far labially that, for the good of the tooth, the 
frail wall of enamel is better cut away, making the two proximal 
cavities confluent with the one on the labial surface. In such an event, 
the mesial and distal cavities may be filled with gold and a porcelain 
inlay inserted in the labial cavity if necessary. A little of the gold may 
be cut away in shaping the cavity for the inlay. 

Fig. 229 Fig. 230 





Class B: Cavities in the Proximal Surfaces of the Incisors and Cuspids 
Which Do Not Involve the Incisal Angle. — These are shown in Figs. 229 1 
and 230. If space between the teeth has been made previously, only by 
a mechanical separator at the time the cavity is being prepared, the gold 
may be inserted at once. It must be borne in mind that all fillings 
upon proximal surfaces, wherever located, are to be given full contour, 
or made to touch, at or near the point of original contact. This is one of 
the fixed laws of a creed that is rigid, and as reasonable as rigid. Satis- 

i Illustrations 229 to 239 are reproduced from Dr. Black's Operative Dentistry and are used in 
this chapter through the courtesy of the Medico-Dental Publishing Company. 



FILLINGS BY CLASSES 219 

factory results can only be obtained by having sufficient space between the 
teeth. The beginner requires more space than the experienced operator, 
and even a little more than is actually needed is far better than not enough, 
because many a contact point has been cut away in finishing the filling 
because of lack of space, which, if had at the time, would have enabled 
the operator to add a little more gold at the contact point. Fillings of 
this order should be made throughout with cohesive gold. The foil 
may be prepared in a rope which has been made from one-half, one-third, 
or one-quarter of a sheet of No. 4 or No. 5 cohesive foil, and then cut 
into lengths of one-quarter, one-half, or even an inch. It should be 
freshly annealed, preferably in an electric annealer, and then laid on a 
tray, covered with white kid or something similar, from which it may 
be lifted with the foil carriers or plugger point. If the cavity be on the 
distal surface of the tooth, and the labial and lingual angles have been 
cut equally, and the approach from the embrasure be equally good, it 
matters little which convenience point is filled first. Most operators 
prefer working from the labial approach. To this end, therefore, the first 
piece of gold is carried into the linguo-axio-gingival convenience point, 
and held there by an instrument in the left hand until the gold can be 
gathered into the angle by the use of the hand plugger. The first piece 
must be thoroughly seated, with no tendency to rock or move, after 
which one, two, or more small pieces may be added to it, and the mass 
well malleted with the hand, automatic, or mechanical mallet. It is 
then well to fill the opposite convenience point in labio-axio-gingival 
angle, working from the lingual approach. After a similar amount of 
gold has been placed in this angle, a piece of gold should be laid across 
from one angle to the other and packed well against the gingival wall. 
The building of gold across this wall should be done with utmost care. 
The piece should not be so large that there will be any clogging in 
failure to reach every portion of the wall. Frequent gentle malleting 
is indicated. The gold should then be carried along the lingual wall, 
gradually working toward the incisal angle, being careful all the. time 
that the fulness be maintained in the direction of the gingival third. 
When the retention point in the incisal angle has been reached, a right- 
angle plugger should be used to carry the gold into that portion of the 
cavity. Unless there be great space between the teeth, this retaining 
pit should be made and filled with right-angle instruments. The 
effort to do this with a bur in the engine is liable to undermine the 
enamel, and to attempt to fill it with a straight instrument or one nearly 
so, and by mallet force is liable to result in an imperfect operation, if 
not the fracture of the incisal angle of the tooth. 

When the incisal angle has been filled, attention should be given to 
the labial wall (Fig. 231). The gold should be packed toward this 
wall as it has been toward each of the other walls, ever bearing in 
mind the form of the finished fillings. Small, foot-shaped pluggers of 




220 THE OPERATION OF FILLING CAVITIES 

the Varney and Webb variety will be found useful in restoring the con- 
tour of the filling. The operator must be careful throughout the oper- 
ation of packing gold, and especially when employing mallet force, that 
he keep a mass of gold constantly between his instrument and the enamel 
wall, lest he chip and fracture that wall, giving it a ragged 
Fig. 231 or serrated appearance. The gold should be given great 
solidity, otherwise it will not take that beautiful finish so 
important in all gold fillings. There seems to be a notion, 
more or less common, that gold cannot be made solid 
unless it be packed exclusively by mallet force. This is 
an error and one that has led to many imperfectly filled 
cavities in the incisor teeth. More labor is required to 
condense a given amount of gold by hand pressure, but 
as great solidity can be obtained by it, and there is not the same danger 
of chipping enamel walls when the hand plugger is used in inaccessible 
portions of the cavity. 

Class C: Cavities in the Proximal Surfaces of Incisors and Cuspids Which 
Involve the Incisal Angle. — The method of introducing the gold in this 
class of cavities does not differ materially from those just described, 
in so far as the gingival third of the cavity is concerned. It does not 
matter whether the filling be started in the linguo-axio-gingival con- 
venience point or in the labio-axio-gingival point. The operator should 
be governed by circumstances. If his approach be better from the 
labial than the gingival side of the embrasure he will preferably fill 
that point farthest away first, and that will be the linguo-axio-gingival. 
This form of anchorage is applicable to teeth of broad incisal edges or 
in teeth which have been purposely made broad upon their incisal 
edges for the purpose of gaining this form of anchorage. 

After the two gingival anchorages have been filled and the gold well 
malleted, additional pieces of gold are added, until the gold has been 
packed across the gingival wall and that portion of the filling brought 
out to its greatest distal or mesial fulness or against the proximating 
tooth. The gold is then built along the linguo-axial wall, as shown in 
Fig. 231, until the incisal step is reached; then along the pulpal wall 
into the angles which have been made by the inverted cone bur, being 
careful that each of these point angles has been thoroughly filkd and 
the gold made solid therein. When this has been accomplished, a 
sense of security may be felt that the gold will not be dislodged. The 
direction of the plugging instrument must be constantly in a general 
line with the long axis of the tooth, and at no time should an angle of 
less than 12 centigrades be used. It should also be borne in mind that 
the force should incline in the direction of the wall to be filled. The 
only way to accomplish that is to drive it in that direction. Gold is 
often driven away from rather than toward the tooth. When the filling 
has progressed thus far the shape of the tooth may be restored, working 



FILLINGS BY CLASSES 221 

gradually from the gingival third toward the middle and incisal third, 
ever bearing in mind the form of the filling at the point of contact. 
Much of the final packing of gold may be done with small foot-shaped 
pluggers. Before removing the rubber dam, or even before a burnisher 
has been used upon the surface of the gold, a careful inspection of all the 
walls should be made, to be sure that at no point has there been a failure 
to get sufficient gold. Special attention should be given to the incisal 
angle. A failure to fill every point along the cavo-surface angles would 
result in early failure of the filling; also, great hardness is needed here; 
otherwise the surface of the gold will be battered by the opposing tooth. 
Platinoid gold is sometimes indicated upon the incisal edge because of 
its greater hardness. 

Class D: Cavities in Proximal Surfaces of Bicuspids and Molars. — It will 
be seen by reference to cuts of these prepared cavities in Chapter 
VII that there is great similarity in the form of cavities in the 
bicuspids and molars. The convenience form has leceived so much 
attention that there is nothing particularly difficult in the introduction 
of the gold. If the teeth have been previously separated, or if a me- 
chanical separator is to be used for effecting space, the operation of 
introducing the gold should follow immediately upon the excavation 
of the cavity. 

There are two methods of starting fillings of this type: The first is 
to fill the cavity throughout with cohesive gold; the other, to use a 
combination of non-cohesive and cohesive gold. We will describe first 
the method of filling throughout with cohesive foil. The preparation of 
the gold for cavities of this description does not differ materially from 
that previously described in proximal cavities of incisors and cuspids. 
A roll made from one-third or one-half leaf of gold may be cut into 
pieces ranging from one-quarter to one inch in length. When the gold 
has been annealed, the first piece is carried to either the bucco-axio- 
gingival or the linguo-axio-gingival point angle, which has been deepened 
into a convenience point for starting the filling. It matters not which 
of these points receives the first piece of gold, provided they are equally 
accessible. If, on the other hand, one is easier to reach than the other, 
the one most remote or hardest to reach should be filled first. The 
instrument a (Fig. 232) in the left hand should hold the gold while it is 
carried into the starting point with a hand plugger b. This first piece of 
gold must be thoroughly seated, after which two or three pieces may be 
added to this and the same malleted to place. The opposite point 
(Fig. 233) should be similarly filled, and then a piece laid across the gin- 
gival wall and connected with that in the two-point angles (Fig. 234). 
Several pieces should be added until the gold has covered the entire 
gingival wall and has been built out nearly or quite across the inter- 
proximal space to the adjoining tooth (Fig. 235). It is at just this 
point that so many failures occur. The gingival third of the cavity 



222 



THE OPERATION OF FILLING CAVITIES 



must have special attention. The cavo-surface angles must be thor- 
oughly covered. Special attention should be given the filling mesio- 
distally. Carry the gold out to the adjoining tooth even though 
it may seem at the time that too much gold is being added. Piece 
by piece should be added until the occlusal step has been reached. 
The operator should hold his plugger at such an angle that the 
gold is being constantly driven against the buccal and lingual walls of 
the cavity, as well as against the gingival. As soon as the build- 
ing of the filling has reached the occlusal step it is well to cover the 
pulpal wall and build back and forth into that which has been placed 
against the axial wall. If the central fossa has been included in the 
cavity and is deep, it is sometimes well to fill this before covering the 



Fig. 232 



Fig. 233 





Fig. 234 



Fig. 235 





entire pulpal wall, as it gives the operator a sense of security lest by any 
means he dislodge the gold already inserted. A few pieces joined in 
this way and well malleted will insure stability. From this point onward 
attention should be given to the proper contour of the fillings. If addi- 
tional space is desired, a turn or two of the screw of the separator may 
be made. It is better to have rather more space than is actually needed 
than to find, when the operation has been completed, that not enough 
gold has been added to make a perfect contact point. The advantage 
of thorough malleting at this point cannot be overestimated. The gold 
should be solid, not only upon the proximal surface, but upon the 
occlusal. Any defect along the margin means a leak and ultimately a 
failure of the filling. Perfect adaptation and great hardness are two 



• 



FILLINGS BY CLASSES 



223 



essentials in all fillings of this class. The other method of starting these 
fillings, as above alluded to, is to fill the gingival third of the cavity with 
non-cohesive gold, used in the form of cylinders or blocks. This method 
has the advantage of greater rapidity and as great, or greater, protection 
to the tooth along its gingival wall. The writer would not assert that 
better fillings can be made by this method, but in the hands of one who 
has become skilled in the use of non-cohesive gold much time can be 
saved, and experience has shown that fillings are equally as good as those 
made throughout of cohesive foil. A half leaf or No. 4 non-cohesive 
foil is folded into a tape or ribbon until its width is a little greater than 
the depth of the cavity from its axial wall mesio-distally. This tape is 
wound upon a flat instrument for an oblong cylinder or a five-sided broach 
for a round cylinder. It matters not which, because the cylinder is 
flattened either before or after it is introduced into the cavity. One 
end of the cylinder is placed against the axial wall, the other projecting 
somewhat beyond the gingival wall into the interproximal space. It is 
usually better to have this cylinder broad enough (Figs. 236, 237, and 
238) linguo-buccally to press upon these walls and be forced into the 



Fig. 236 



Fig. 237 



Fig. 238 






bucco-axio-gingival and the linguo-axio-gingival angles. If a single 
cylinder is used, it should contain a considerable quantity of gold, and 
after being matted down in a general way with a broad-faced plugger, 
then a piece of cohesive gold should be carried into the bucco-axio- 
gingival and the linguo-axio-gingival point angles, taking with it a 
portion of the cylinder which has been mashed against the buccal and 
lingual borders of the cavity. An instrument in the left hand will aid 
the operator in holding the cylinder in place until he has made it secure 
in the point angles, as above. The mallet may now be used and the gold 
thoroughly condensed against the gingival wall, after which cohesive 
gold should be used to complete the filling. Another method of using 
non-cohesive gold in such cavities is to use three cylinders, placing one 
toward the buccal, one toward the lingual wall, and then one between 
the two which acts as a key. As the middle one is forced toward the 
gingival wall the others are pressed laterally, after which the cohesive 
gold is inserted as above described. 

When filling distal cavities of the class under consideration, the 



224 THE OPERATION OF FILLING CAVITIES 

matrix is often used. It is thought by many to simplify the starting 
of the filling. One end of the cylinder rests against the matrix, the 
other against the axial wall. It unquestionably does assist in holding 
the cylinder within the cavity and makes the seating of the filling much 
easier. If the matrix be made of thin copper and securely lashed to 
the tooth with floss silk and wedged securely against the gingival border 
of the cavity, it does answer a good purpose and may be used to advan- 
tage, but as great care is necessary when packing the gold around the 
cavo-surface angles, and perhaps greater danger of imperfections at these 
points than when no matrix has been employed. In mesial cavities, 
the matrix obstructs the light and should seldom be used, except when 
amalgam or one of the plastics is to be used as the filling material. 

Special consideration should be given to the manner of packing the 
gold in this class of cavities, and in fact in all cavities which are to be 
filled with gold. A hap-hazard way, with a thrust here and a blow from 
the mallet there, does not make fillings of uniform density, nor does it 
make fillings with tight margins. After placing a piece of gold at a 
certain point, the whole surface of that piece should be gone over with 
the plugger point step by step, each move of the plugger point being not 
greater than its own diameter. It would be well if the operator could 
have in mind an imaginary line drawn bucco-lingually through the 
centre of the cavity being filled and from that central line direct his force 
axio-lingually and axio-buccally (Fig. 239). When the cavity to be filled 
is as far back as the distal surface of the second molar, direct access to 
such cavities is difficult, especially in the lower teeth, and to get direct 
force with pluggers of a single curve is impossible. Much of the packing 
of gold in these cavities must be done by hand pressure, or by the use of the 
reverse plugger and mallet force. It is thought by many that the matrix 
is indispensable in cavities of this kind, but unless great care be taken, 
imperfect margins will be the result. If amalgam were the material 
under consideration, the matrix would be most useful and always indi- 
cated. 

The process of packing gold in these large cavities, unfavorably 
located, is, in the nature' of things, slow, but if good and lasting results 
are obtained by the use of gold, each step in the operation must be 
painstaking and thorough 

Class E : Small Cavities on Occlusal Surfaces of the Bicuspids and Molars. — 
These are among the simplest in form and may be quickly filled with 
gold of the non-cohesive variety, if used in the form of tape, or with the 
machine-rolled cylinders found in the dental depots and known as semi- 
cohesive. Those in the bicuspids are usually regular in form and need 
no additional resistance or retention shape. When the cavity has been 
four-fifths filled, cohesive gold should be used for surfacing, and if 
throughout the operation mallet force has been used freely, a thoroughly 
good filling will be the result. Cavities of this character, although of 



FILLINGS BY CLASSES 225 

greater size, are found in the molars, and may be filled in the same 
general way. Mats of foil may be substituted for tape; or, where the 
cavity is very large, the gold may be introduced in the form of cylinders. 
It not infrequently happens that a large portion of the occlusal surface 
of a molar is lost by decay and that the four walls surrounding the cavity 
are strong. Such cavities may be filled, with a great saving of time, by 
the use of cylinders. Before the introduction of rubber dam, when the 
dentist was obliged to control the saliva by means of the napkin alone, 
time was a great consideration, and cylinder filling was more generally 
practised then than now. Excellent results can be accomplished by this 
method, and it were well if the young men who are now entering the 
profession would learn to use non-cohesive gold, but it is better that 
the beginner first become proficient in the use of cohesive gold lest he 
become confused in his attempt to learn too many methods at the outset. 
Cylinders for such cavities (Fig. 240) should be hand-made and of 

Fig. 239 Fig. 240 





Occlusal cavity with cylinders. 

No. 4 non-cohesive foil. They should be long enough to reach from 
the pulpal wall to a sixteenth of an inch above the occlusal surface 
of the tooth. The first one should be placed at the most distal point in 
the cavity, then cylinder after cylinder is placed around the walls until 
the buccal, lingual, and mesial walls are covered. Each one in its turn 
is pressed against the walls with strong wedge-shaped instruments. As 
often as room can be made in the centre of the mass, another cylinder 
should be placed, and the same lateral pressure applied. When no other 
cylinders, not even the smallest, can be forced into the filling, the surface 
of the gold should be thoroughly condensed by the aid of the mallet, 
and this repeated until a very hard surface has been secured. This 
method is better suited to mortise cavities with flat pulpal walls, and 'the 
four other walls parallel, or nearly so. 

From the foregoing classification of cavities and the special manner of 
treating each class, the reader may infer that all cavities which are to be 
found upon the proximal surfaces of teeth, no matter what may be the 
conditions surrounding them, are to be extended buccally and lingually, 
gingivally and incisally, until the greater portion of the proximal surface 
of the tooth has been cut away. But such is not the intention in every 
15 



220 THE OPERATION OF FILLING CAVITIES 

case. The rule is to place all cavity margins on areas that are practically 
immune from caries, but that zone of immunity is not the same in all 
teeth, and it is for this reason that the writer would depart from the 
habit which has become quite general, namely, sacrificing a larger 
amount of tooth structure than is demanded for the preservation of the 
tooth. Reference is made to the exceptionally small cavities that are 
sometimes to be found in the anterior teeth (incisors and cuspids) at or 
near the point of contact. Experience and observation have shown that 
there are certain teeth which have small points of contact and open 
embrasures in which the initial decay is small and has been slow in its 
progress, with no tendency to spread over an area larger than the head 
of a small pin. To cut the entire mesial or distal surface away that 
the rule may be observed is wanton destruction of tooth substance, 
and in thousands of instances uncalled for. The writer has seen fillings 
placed in these small cavities which have lasted fifty years or more, with 
no recurrence of decay. If the dentists of a half-century ago could fill 
such cavities with non-cohesive foil and make the tooth good for a life- 
time, surely the dentist of today, who understands the nature of caries, 
and the means of preventing it, who has grasped the principles of sus- 
ceptibility and immunity, and, in addition thereto, has the benefit of the 
increased facilities in operating, surely better results, if possible, may 
reasonably be expected at his hands. This is a plea for small cavi- 
ties in the anterior teeth, in which the structure is good and the 
embrasures broad. Such cavities may be shaped in the same general 
way as those heretofore described, and may be filled, either with non- 
cohesive gold, in the form of tape, or with cohesive gold, prepared in 
any form desired; the lingual and labial walls left intact, or, if it may 
seem best, the lingual angle may be cut away and the approach to the 
cavity be from the lingual surface 

FILLING WITH TIN 1 

It is not definitely known when tin was first employed for filling 
carious teeth, but it has been used for at least a century and has found 
great favor with many. Prior to the improvement in the formulas of 
dental amalgams, tin was used more generally than at the present time. 

Tin possesses certain inherent characteristics which make it valuable 
as a filling material. Among these are great malleability, non-con- 
ductivity, and it is thought by many to possess antiseptic properties. 
But while it has desirable qualities, it has also some undesirable ones, 
such as softness, and when exposed to the secretions of the mouth it 
discolors — which facts render it unfit for surfaces exposed to great wear 
in the act of mastication and upon surfaces exposed to view. The 

1 The physical and chemical properties of tin in connection with its use as a filling material are 
discussed in detail in Chapter XI, p. 319, 



FILLING WITH TIN 227 

discoloration, however, is confined to the surface, and teeth filled with 
tin are not discolored in consequence of its presence. 

There are various methods of preparing tin for dental purposes. 
That which has found greatest favor in the past is in the form of foil. 
The tin used should be chemically pure. An ingot of the metal is 
rolled into ribbon and then beaten, after the same manner as gold foil, 
into sheets of the desired thickness. As a rule, it is not beaten as thin 
as the former. The foil best suited for most fillings is No. 4. 

Pure tin, like pure gold, is cohesive, and fillings of considerable solidity 
can be made if the operator will exercise care in packing it. The best 
results are obtained by taking a third of a leaf of Xo. 4 foil and rolling 
it into a loose rope, then cutting it into lengths of half an inch or less 
and packing each piece with a view of making each part of the filling 
solid. Some prefer holding the sheet with a spatula after the same 
manner as gold foil, and then cutting into narrow tape. Equally good 
results are obtainable by either method. 

A more rapid but less satisfactory manner of introducing the filling 
is to use the tin in the form of cylinders, not relying so much upon the 
cohesive properties of the metal. The directions for using gold in the 
form of cylinders will apply equally well for inserting tin foil. 

Shavings of Tin. — The cohesive property of tin is best illustrated when 
it is used in the form of freshly cut shavings from a revolving ingot of 
the metal. Any operator can prepare his own shavings and have them 
fresh daily or hourly, if necessary, after the following method: Take an 
ordinary corundum wheel two inches in diameter and one-half inch in 
thickness, such as is used in the laboratory. Make a mould of this in 
sand or marble dust, then melt in a crucible or ladle enough pure tin to 
fill the mould. When it has been poured and cooled, mount accurately 
upon the mandrel of the laboratory lathe, and from it, with a sharp 
carpenter's chisel, turn shavings of great tenuity. When freshly cut, 
and before oxidation of the surface has taken place, by exposure to the 
atmosphere it will be found that the tin coheres with the same readiness 
that pure gold does. Broken-down teeth can be built up by this method, 
or by means of it surfaces may be contoured as with gold. 

The plugging instruments best adapted for tin filling are those having 
shallow but well-defined serrations and points not too broad. As the 
margins are approached, broader points and condensers may be used, 
and the surface should be well burnished. The operator must not lose 
sight of the fact that while tin possesses many desirable qualities and is 
easily manipulated, it lacks hardness and is not adapted to surfaces where 
great attrition occurs. Its chief value is found in its use upon surfaces 
concealed from view and shielded from wear, and in the temporary 
teeth, where its greatest value is manifest. 

Tin fillings should be finished with the same care as gold ones, and 
the same directions will apply in all particulars. 



228 



THE OPERATION OF FILLING CAVITIES 



FINISHING FILLINGS 

Much of the beauty and utility of a filling depends upon the way it is 
finished. It is not enough that it be well made; it must be well finished, 
if the best results are to be attained. All fillings should contain rather 
more gold than it is intended shall remain, and this for the purpose of 
dressing down to such lines as shall be both practical and esthetic. 

Fillings that are not solid and well condensed throughout their entire 
surface cannot be given a fine finish. 

After the last piece of gold has been added and the whole surface of 
the filling gone over with a plugger with shallow serrations or with no 
serrations at all, a thorough burnishing with a burnisher that is abso- 
lutely smooth, should be given the surface of the filling. By this means 
the gold is made more compact and the margins are sure to be well 
covered. This does not mean that imperfect margins can be made 
good by a burnisher, but a good thorough burnishing brings the gold 
in absolute contact with the enamel margins. 



Fig. 241 



Fig. 242 




Plug finishing burs 



I 1:1 

Wood polishing points. 



The small fillings upon occlusal surfaces (and all pit and fissure 
cavities) are best dressed down with finishing burs, as shown in Fig. 241. 
They are finely cut and leave the gold with a more uniform surface than 
when cavity burs have been used for the purpose. The gold should be 
cut away until the cavo-surface angle has been reached, and until all 
overlapping of gold has been removed. The occlusion of the tooth of 
the opposite jaw should be noted, and if it strikes unduly upon the filling, 
enough should be taken from the surface of the gold to prevent it. When 
a uniform surface has been given to the gold, a suitable wood point, 
as shown in Fig. 242, should be mounted in an engine mandril made 
for that purpose and the point dipped first in water and then in fine 
pumice powder and the surface nicely smoothed. After which a round- 
end burnisher may be used, if the operator desires a polished surface, 
although it adds nothing to either the beauty or the utility of the filling. 

When fillings cover a larger portion of the occlusal surface, the cutting 
of the gold may be done with corundum or carborundum points and 
wheels, which, if kept constantly wet, cut more rapidly than burs 



FINISHING FILLINGS 



229 



and cause less heating and less discomfort to the patient. These are 
shown in Fig. 243, and are of many patterns, and admirably adapted for 
the purpose intended. Those made of fine corundum and shellac, or 
corundum and vulcanized rubber, are more desirable than the coarse 
ones, which are liable to grind away the cavity margins because of the 
rapidity with which they cut. 

Fillings upon labial and buccal surfaces should be dressed down with 
fine stones, such as the Hindostan, or any variety that has fine grit, 
until the outline of the cavity is reached. Any overlapping of gold upon 
these surfaces gives a ragged appearance to the filling and detracts 
much from its beauty. Care should also be exercised in giving the 
filling the same degree of convexity that the tooth formerly had — in other 
words, the filling should accurately restore the lost anatomical contour 
of the tooth. 

Fig. 243 




Corundum points. 



Fig. 244 




TTTY 




Hindostan points. 

When sufficient gold has been removed the surface should be nicely 
smoothed with revolving wood points, charged with pumice powder 
and water, or a paste made of pumice and glycerin, after which the 
final finish may be made with flour of pumice, chalk, or oxid of tin, 
used by means of a revolving disk or wheel of felt, leather, or rubber. 
As fillings upon the labial surface are more or less conspicuous at best, 
it is better not to give them a burnished surface. The "dead" or 
satin-like finish which is left by the flour of pumice is usually preferred. 

Fillings upon proximal surfaces are more difficult to finish, and too 
great care cannot be bestowed upon them. An operator is often judged 
by the finish that he gives his proximal fillings, and justly so, as no 
class of fillings requires a higher degree of skill in the finishing. 

In olden times, when no effort was made to restore the natural contour 
of the tooth, fillings were made flat, and a file was about the only instru- 
ment required in the finishing of such fillings; but the day of flat fillings 
has passed, and the separating and finishing files of our fathers have little 
use in the cabinet of the present-day dentist. The whole method of 



230 THE OPERATION OF FILLING CAVITIES 

finishing fillings upon proximal surfaces has changed, and a new line of 
instruments suited to this method has been evolved. There is of neces- 
sity more or less overlapping of gold in the insertion of a filling, and the 
removal of all excess is as important as any other part of the operation. 
For this purpose a variety of instruments is supplied. In the selection of 



Fig. 24.5 



I 








16 17 18 19 20 21 22 23 24 25 26 27 

Finishing files and knives. 



31 



32 



Fig. 246 




Curved finishing files. 



these the operator should bear in mind that he has a contact point to pre- 
serve, and he should avoid the use of such instruments as may cut away 
the thing of greatest importance, and the one most liable to be destroyed. 
To this end, separating files are practically to be eliminated, but in their 
stead gold trimmers of various patterns are to be used. In Fig. 245 are 



FINISHING FILLINGS 231 

illustrated some of those most useful. The gingival wall is generally the 
one to receive attention first, and if the conditions are such that the 
separator and rubber dam can be left in place until the gold which over- 
laps at the gingival borders has been trimmed away it will add much to 
the ease of finishing that portion of the filling. It is well in all instances 
to retain the separator as long as it can be done without interfering with 
one's ease of manipulation, because it is often desirable to lift the teeth 
apart a little for the purpose of passing thin finishing strips between, 
although, as a rule, it is better to pass nothing between the points of 
contact, or what is to be the point of contact, until nearly the last 
thing. The knives and finishing files shown in Fig. 245 should be 
used for cutting away any overlapping gold at the gingival wall of 
the filling; also for dressing down the lingual and buccal borders. 
A finishing strip may be threaded through the interproximal space 
above the proposed point of contact and worked back and forth. 
Sometimes as many as a half-dozen pieces should be used in getting the 
gold down to the walls, but it should be understood that these finishing 
strips are not to be passed back and forth from the occlusal surface, 
and that their use at this stage is to be confined to the gingival third of 
the embrasure. Attention may now be given to the lingual and buccal 
margins. If the filling extends well toward the lingual and buccal angle 
(and it is to be presumed that it does) a disk of corundum may be used 
very cautiously for cutting down the greater portion of the overplus gold, 
but in the hands of a beginner it is safer to confine one's self to the hand 
files and trimmers. The same may be said of the sandpaper disk if used 
too freely. The one point above all others is to avoid cutting away the 
contour which has been laboriously made, and so destroy the contact 
point, which is of vital importance in the comfort of the patient and the 
future welfare of the tooth. Under the most favorable conditions, the 
finishing of fillings in the proximal surfaces of the bicuspids and molars 
is slow, often consuming as much time as the insertion of the filling, but 
when done with care and the result which has been attained it is well 
worth the time and effort expended. Attention should now be given 
to the proximo-occlusal angle and the occlusal surface. At this point 
stones, revolving in the handpiece of the engine, may be used, but they 
should be so shaped that they will not by any possibility cut away the 
gold unduly from the proximo-occlusal angle. When the gingival third 
of the filling has been finished and the contact point preserved, the rubber 
dam may be removed, and the further dressing down of the occlusal and 
proximo-occlusal surfaces done with a wet wheel, which lessens the friction, 
and consequently the heat, which is often distressing when using burs or 
wheels of any kind in a dry state. Special attention should now be given 
to the articulation of the filling in occlusion with the teeth of the oppo- 
site jaw. If the contact be with the gold, it should be cut away until the 
patient notices no undue pressure upon any portion of the filling. A filling 



232 THE OPERATION OF FILLING CAVITIES 

just a little too full is unpleasant to the patient; one much too full is a 
cause of danger to the filling and surrounding walls, and possibly to the 
pulp or pericementum. Before the final smoothing of the filling is done 
with fine powders, one last attention should be given to what will be the 
future point of contact. It is presumed that up to this time every other 
portion of the filling has been dressed into final shape, and it is possible 
to do all of that with the trimmers and other means provided; then, as a 
final touch, before using the buffing wheels, a strip charged with fine 
buckhorn or silex may be passed a few times over the contact point, 
and from that moment nothing more than a smooth burnisher should 
touch it. If, however, the separator has lifted the teeth apart suffi- 
ciently, and the operator is assured that he has space to spare, he may 
pass back and forth between the teeth a piece of thin linen tape, first 
made wet and then charged with some fine polishing powder, such as 
chalk, oxid of tin, or buckhorn. When this has been done, and the 
occlusal portion has received the same careful treatment, the filling may 
be considered finished. Burnishing adds nothing to its appearance or 
utility, and if in a position to show, only makes it more glaring and 
manifest. The same general treatment in the matter of finishing fillings 
upon proximal surfaces of the incisors and cuspids obtains and a special 
description here is unnecessary. 



REPAIRING FILLINGS 

Fillings somewhat defective are often susceptible of repair. The 
defect may sometimes be apparent in the finishing; at other times it 
is the result of subsequent caries, and at still other times the result of a 
fracture of the enamel along the border of the filling. 

The nature of the defect and the condition of the remaining filling 
must be taken into consideration before an effort to repair is undertaken. 

When the defect is due to insufficient gold at any point in the filling 
more gold may be added. It is well to first cut out a portion of the 
filling, making a distinct cavity of retentive shape. Cohesive gold is 
usually best suited to the purpose; crystal gold often serves well in the 
repair of such defects. 

If the filling has been thoroughly condensed and the mass is solid 
there is little difficulty in adding more gold to it, provided the surface 
be clean. If it has been wet with saliva, the surface of the gold must be 
made not only dry, but clean. It is well to wipe it with a pellet of 
cotton or paper saturated with absolute alcohol or ether, after which 
the filling should be scraped with a suitable instrument. If the filling 
be of considerable size and well anchored, shallow retaining points may 
be drilled into it, which will make an additional hold for the gold which 
is to be added. Defects which arise from subsequent caries are perhaps 



REPAIRING FILLINGS 233 

more frequent in proximal surfaces at or near the gingival margin. 
These borders are vulnerable points for the recurrence of caries, and 
imperfect adaptation is not infrequently the determining cause of the 
beginning of such decay. 

To effect a successful repair in such localities ample space should be 
obtained, especially so if the repair is to be made with gold. 

If the decay has not extended beneath the filling, and sufficient 
space has been obtained, there is no greater difficulty in making a suc- 
cessful repair than in filling a simple cavity similarly located. If the 
operator is skilled in the use of non-cohesive gold, he will do well to 
prepare his foil in the form of narrow tape, and work it into the cavity 
fold after fold, allowing the loops to extend somewhat above the walls 
of the cavity. When the cavity has been completely filled the protrud- 
ing folds may be well condensed and the filling finished in the usual 
way; or the repair may be made with cohesive gold, the first piece 
having been made fast in a groove or retaining point. 

Such repairs are often required in the bicuspids and molars, and 
large fillings otherwise good are saved by a successful repair at the 
cervix. The plastics are sometimes indicated in this class of cases, 
provided they be not so near the anterior part of the mouth as to be 
unsightly. Gutta-percha often serves a good purpose here, but in some 
mouths undergoes decomposition and is less reliable than gold. The 
oxyphosphates are contraindicated because of their liability to wash 
away after a few months. Amalgams are more frequently used, and 
nearly always serve well when thus employed; but unfortunately the 
contact with gold produces discoloration, and an unsightly filling is the 
result. Whenever gold and amalgam are brought in contact in the 
same tooth, if the surface of each is exposed to the fluids of the mouth, 
the amalgam is almost sure to turn quite black. The discoloration of 
the surface of the alloy does not lessen its value as a preserver of the 
tooth, but its unsightliness is often too great to be tolerated; neverthe- 
less, utility enters so largely into the equation that the operator feels 
justified in using the alloy, because with it he feels sure of making a better 
repair. After the alloy has hardened it should be nicely dressed down 
and all overlapping of the material at the gum margin removed, when it 
should be smoothed and polished with the same care that other fillings 
receive. 

Fracture of one or more of the cavity walls is a common accident, 
and one which may be repaired if the filling has been securely anchored 
in portions of the tooth not involved in the fracture. Such accidents 
sometimes befall bicuspids and molars, especially the bicuspids, where 
fillings have been inserted in each proximal surface, the two meeting 
upon the occlusal surface. The buccal wall is sometimes the one broken 
away, sometimes the lingual. In either case the ability to successfully 
repair depends upon the stability of the proximal fillings and the anchor- 



234 THE OPERATION OF FILLING CAVITIES 

age which can be obtained at the gingival wall and in the exposed 
fillings. To restore with gold a buccal cusp or the entire buccal surface 
of a bicuspid might necessitate a show of gold which would be objection- 
able; and a better plan would be to engraft a porcelain facing or an 
entire porcelain crown; whereas such a restoration on the lingual sur- 
face would not be open to the same objections. Cohesive gold alone is 
indicated for repairs of this kind. Watts' crystal gold when used in 
cases of this description has been most satisfactory. 

If the fracture extends above the margin of the gum the operation 
is much more difficult because of the danger from a flow of blood, and 
the additional difficulty of getting the rubber dam above the border 
of the fractured surface. This may be accomplished by filling for a 
few weeks with gutta-percha, when there will be recession of the gum 
caused by the pressure of the gutta-percha upon it. When a similar 
fracture occurs in a molar, if the fractured surface does not encroach 
upon the pulp, and will admit of drilling retaining points without danger 
to the pulp, there is no difficulty in restoring the broken portion with 
cohesive gold. Mack's screws are sometimes indicated in cases of this 
kind, since strong anchorage can be secured in this way without much 
loss of tooth substance. 

Fracture of the incisal angle of the anterior teeth is often a serious 
accident, because of the difficulty of repair and the unsightly display 
of gold when it has been accomplished. 

Large fillings situated upon the proximal surfaces of the incisors but 
not extending to the cutting edge, jet near enough to weaken the enamel 
overhanging, are especially liable to need repairs. The corner of the 
tooth breaks away, leaving the surface of the gold exposed, and the only 
hold the filling has is at the gingival border. In order to secure retaining 
hold for additional gold the operator must be careful not to displace the 
original filling. A wooden wedge should be inserted between the teeth 
and pressed home with sufficient force to hold the filling securely in 
place during the operation of repair. Sometimes a retaining point can 
be made laterally into the sound dentin, or, by cutting a little channel 
through to the lingual surface and then deepening the channel at its 
extremity with a round bur, a secure anchorage may be had for the 
fresh gold. 

Great care should be exercised in packing the gold, lest by inadver- 
tence the instrument should slip and push the original filling from its 
position. Fractured surfaces should receive prompt attention, for if left 
for a period of time disintegration of the dentin will set in and the caries 
may extend beneath the filling and thus jeopardize or ruin the most 
thorough work. 



CHAPTER X 

USE OF THE MATRIX IN FILLING OPERATIONS 

By WILLIAM CRENSHAW, D.D.S. 

The matrix, as originally suggested and employed, was used exclu- 
sively between the molars and bicuspids, and consisted of curved pieces 
of thin metal of various kinds, which were braced with wooden wedges 
from one tooth to the other; but now the matrix has been adapted to other 
teeth and other forms of cavities, as will appear in the further develop- 
ment of this subject. All forms of cavities occurring on molars, bicus- 
pids, and incisors, standing alone or together, excepting those cavities 
located in the occlusal surfaces of the first-mentioned class, and in the 
cutting edges and corners of the latter, are now subject to the use of the 
matrix as an aid in filling them. 

The large and difficult filling operations encountered between the 
molars and bicuspids, which in past decades so taxed the skill and vitality 
of the dentist, have been by various forms of device rendered easier of 
execution and more permanent and perfect in character. 

Matrices have been used more or less in one form or another for the 
past fifty years, and some crude forms even longer. Dr. Louis Jack gave 
the profession thirty years ago the first practical idea and demonstration 
of the matrix and its possibilities, and his effort, more than all that had 
gone before, gave shape and impetus to the development of this important 
device. 

GENERAL CONSIDERATIONS 

The limitations, no less than the possibilities, of the matrix are im- 
portant to understand, because, used indiscretely, in locations which the 
judgment should forbid or in locations where it would be perfectly in 
place but for the unsuitable nature of the material employed, more harm 
than good may result from its use. To be able, therefore, to discern the 
proper class and location of cavities for the reception of the fillings, 
together with a knowledge of adapting the filling materials to the case 
in hand, are some of the requirements and demands on the operator who 
essays to use matrices. 

The matrix should possess as fully as possible the qualities of adapt- 
ability and fixedness to the teeth, at the same time provide for contouring 
and for leaving the teeth in proper position, and preserving the proper 

(235) 



236 USE OF THE MATRIX IN FILLING OPERATIONS 

interproximal space. Further desiderata are that the matrix shall he 
resistant enough to stand the pressure of condensing gold against it, 
susceptible at the same time of being shaped into whatever form needed, 
and capable of being removed from between the teeth without destroying 
the form of the filling after that has been completed. 

The material of which the matrix is made depends somewhat on the 
location and class of the cavity to be filled. 

In many of the operations occurring between molars and bicuspids, 
particularly in the instances where only one tooth is decayed and only 
slightly so, slips of German silver or steel (36 to 40 gauge) may be inter- 
posed and used. In the instances where gold is to be the filling, and the 
cavity is of large size, the metals above mentioned, silver and gold plate, 
but of heavier gauge, and other substances may be employed. But in 
the event of the matrix band having to bear heavy tension, which tests the 
strength of it, as in the loop or band variety or any duplex form which 
separates the teeth, either decarbonized steel or phosphor-bronze, the ten- 
sile strength of which is equal to or beyond that of steel, should be used. 
Steel is somewhat unsatisfactory, because if bent often at one place it 
breaks, and it does not hold polish or plating well. Phosphor-bronze 
not only polishes and holds plating well, and does not corrode, but solders 
readily to gold, silver, German silver, steel, copper, and brass, and does 
not soften or amalgamate with the mercury employed in amalgam alloys. 

The matrix band should be closely adapted around the margin of the 
tooth cavity, and the cavity floor and walls coming up to the band 
should form as nearly as possible right angles with the band. This rule 
followed, with the employment of proper forms of instruments, will be 
found to insure well-condensed margins, and as full a contour as ordin- 
arily belongs to the tooth of its class; and, in those instances where it is 
desirable, greater contour than belongs to the tooth may be produced. 

Those devices which when assembled are practically in one piece, and 
admit of easy application and steady fixedness on the teeth, with as little 
of obstructing parts as possible, are the ones with which the operator 
will ordinarily accomplish best results. The bands should not purposely 
stand away from the tooth. This is impracticable even if it were desir- 
able, as there are no means for holding the band away from the tooth and 
at the same time having it secure from slipping and working loose under 
the operation of the filling. Occasionally in cavities occurring on the 
mesial side of upper first and second molars, and more frequently on both 
the mesial and distal sides of upper first bicuspids extending well under 
the gum, we encounter the concavity occasioned by the bifurcation of 
the roots, when of necessity the band stands off from the depression. 
The filling, however, whether of gold or tin foil, is not better condensed 
at this point for that reason. 

The failures made with the matrix result quite frequently from the 
selection of a wrong material. Take, for instance, any of the proximal 






\. 



GENERAL CONSIDERATIONS 237 

surfaces of the molars or bicuspids in which the cavity extends beyond 
the margin of the enamel, presenting ideal conditions for the employment 
of the matrix; prepare these cavities after approved methods, apply the 
matrix, and fill with any form of cohesive gold, and we have a filling 
beautiful in appearance, but more treacherous than beautiful, and one 
which will develop recurrent decay along the cervical margin sooner than 
would result from the employment of any other filling material placed 
in the permanent list. 

It will not matter what form of cohesive gold is employed, if heat 
sufficient to change its molecular arrangement has been applied in anneal- 
ing the gold, it is practically impossible to adapt it, unaccompanied by 
linings, so as to secure moisture-proof joints, and therefore permanent 
results. Because, first, the tooth does not afford the resistance necessary 
to reduce the crystals of gold into adaptable laminae, and we have the 
crystalline gold resting on fibrous structure in the cementum and dentin, 
which together prevent the making of moisture-proof joints. Therefore, 
this state of affairs, aided either by the creeping in of fluid at the base of 
the filling from the canaliculi and lacunae, or drawing in external moisture 
by capillary attraction from without, permits of recurrent decay. With 
cohesive gold, the result would be ultimately the same, with or without 
the matrix; although the work would, should at least, be better executed 
without it. But with the cavity well prepared, and the matrix securely 
adjusted, the operation is inviting in appearance, and the operator is led 
into a snare and delusion when he essays to fill these points with cohesive 
gold exclusively. 

The objection here raised to cohesive gold does not apply to the same 
extent in adapting it to enamel walls, because in this tissue we have an 
absence of nerve fibers, and a greatly denser substance against which to 
adapt the gold. While it is impossible to adapt cohesive gold to tooth 
structures so as to stop out moisture permanently, for the reason pointed 
out, there is that difference in the histological make-up of the tissue of 
cementum and dentin and enamel which explains the fact of cohesive 
gold being better adapted to enamel, and can be made to better prevent 
the leaking of moisture than in cementum margins. Again, decay cannot 
be so rapid in enamel margins, because of its inherent strength and 
resistance, due in part to the absence of nerve fibers and to its greater 
density and hardness. 

The propaganda of Prof. Henry S. Chase — namely, that in propor- 
tion as teeth need saving gold is the worst material with which to do it — 
is true in its application to cohesive gold, particularly in cementum and 
dentin margins in connection with the matrix. But substitute non- 
crystalline or soft gold in these margins, and we pass from the worst 
possible work done with gold, and made even worse by the employment 
of the matrix, to that which has proved the best possible — at least up to 
the present time. 



238 USE OF THE MATRIX IN FILLING OPERATIONS 

Cohesive gold is at its best in open cavities with strong enamel mar- 
gins, and is profitably employed in cervico-occlusal fillings in connection 
with soft gold and matrices to cap over the proximal wall of soft gold. 
Cohesive gold, on the other hand, is at its worst in connection with mat- 
rices when used at the cervical margins, particularly when the margin 
is located in cementum or dentin, because of the physical difficulties 
encountered in the adaptation of it, and the perishable nature of the 
margins on which it is laid. 

Again, in the employment of a carelessly formulated and compounded 
amalgam alloy packed into these cavities embraced by a matrix, depend- 
ing too much on the matrix, as is the tendency, we have another instance 
in which the inefficiency of this device is made to appear. 

It should be made a rule of practice in employing the matrix to regard 
it simply as a mechanical device, the object of which is to simplify com- 
pound and other difficult cavities; and not to depend on it to make good 
any of the essentials of the filling material. With this idea in view, and 
fortified by a knowledge of the essential characteristics of materials rather 
than matrices, we shall know where and when to employ them. The 
filling materials, too, must possess constancy of form, and susceptibility to 
that perfect adaptation which shall prevent the drawing in of moisture by 
capillary attraction, the result of which would be recurrent decay. An 
understanding of these characteristics is indispensable to the permanence 
of filling operations anywhere and everywhere, and by whatever method 
performed, and when they are thus understood, combined with the 
advantages afforded in the use of the matrix, the operator will accomplish 
his best results. The matrix should be used, therefore, for the purpose 
of simplifying the cavity, and never allowed to lead into the use of a 
treacherous and questionable material. 

The matrix is valuable in all those cavities of extreme decay involving 
the disto-occlusal, the mesio-occlusal, the bucco-occlusal, the disto-bucco, 
the mesio-bucco, and the disto-linguo and mesio-linguo occlusal surfaces 
of molars and bicuspids. In many instances the entire corners may be 
restored, as is intimated and included in the disto-bucco and mesio-bucco, 
the disto-linguo- and mesio-linguo-occlusal surfaces. No method jet 
devised for filling these teeth is so satisfactory or productive of such 
results as when the matrix is employed, as it aids the adaptation of the 
material definitely and exactly in position. Its chief advantage is in 
having brought a cavity of compound and complex nature into simple 
form, and so contributing to the mastery of the material that perfect 
adaptation and condensation is secured. 

A comparison cf results at the cervical margin between fillings made 
of soft gold and those of the cohesive variety shows in so marked a degree 
in favor of the soft, even in operations where the matrix has not been 
used, that when this device is employed it places the standard of excel- 
lence of soft-gold work far above that of the cohesive. 



CAVITY PREPARATION FOR MATRIX WORK 239 

With the advantages thus accruing, soft gold in the form of cushions 
or cylinders may be perfectly adapted at the cervical aspect and as far up 
the wall as desired, capping over with a slab of cohesive which, when 
anchored in the occlusal surface, makes a handsome and lasting operation. 

Another treatment of these cavities is to place tin cylinders or cush- 
ions, which may be made by folding the cylinders upon themselves, and 
adapt at the cervical margin and up the cervico-occlusal wall to the top 
of the step d, Fig. 247, completing with the slab of cohesive gold or of 
amalgam for the remainder of the filling. (See Fig. 251.) The soft 
gold and the tin are practically the same in adaptation, due to the fact 
that in their manufacture the molecular arrangement is destroyed and 
becomes structureless, by which a closer and more perfect adaptation is 
possible. The matrix enables the operator to take advantage of this 
important quality; and without thus simplifying the cavity, it would 
be quite impossible to confine, control, and condense these materials, and 
secure adequate solidity and adaptation to margins. 

The use of the matrix, therefore, not only enables the operator to 
place soft gold in a satisfactory manner at the points where it serves best, 
but also cohesive gold where it is best adapted — namely, at enamel mar- 
gins, and in that portion of the filling where it is most easily and perfectly 
adapted. Again, cohesive gold is placed in matrix work at that point 
where it best resists the attrition and stress of chewing, and the lateral 
wear between the teeth. 

Still another treatment of these cavities in connection with the matrix 
is with amalgam alloy. 

Assuming that the same care and pains have been taken with the 
preparation of the cavity for the amalgam as for the gold, the simplifying 
of it by the use of the matrix enables the operator to secure greater 
solidity and correspondingly better adaptation to the walls of the cavity. 
This material, used in connection with the matrix and cavity lining, 
places amalgam alloy on a plane not heretofore occupied by it. In the 
large proportion of cavities occurring in the class under consideration, 
this practice stands for much in the saving of these teeth. 



CAVITY PREPARATION OF THE MAJOR CLASS FOR MATRIX 

WORK 

The subject of cavity preparation comes up in connection with the 
matrix as a matter of first importance. 

The form of cavity preparation ordinarily employed in cases of extreme 
decay of proximal surfaces of molars and bicuspids answers in some 
measure in matrix work. 

In the description of cavity preparation the terms depth, width, and 
length, as applied to the several walls of the cavity, should be limited, 



240 



USE OF THE MATRIX IN FILLING OPERATIONS 



and apply to particular points, and particular points only. For instance, 
the depth of a cavity should mean from the point of decay toward the 
pulp, whether penetrating from the occlusal, mesial, distal, buccal, or 
lingual aspect of the tooth. The width should mean from side to side 
of the cavity, whether on the occlusal, mesial, distal, buccal, or lingual 
surface of the tooth. The length, the longest dimension, should mean 
the greatest length, in whatever direction it extends. The bottom of 
a cavity should be called the floor, as seen at A and D, Fig. 247. By 
reference to Figs. 247 and 248 the tooth shown represents a left lower 
molar, the decay of which penetrates from the mesial surface in the 
direction of the line leading from f, and we would say that the depth 
of the cavity seen at a and c was in that direction; and that its width 
was bucco-lingual, from e to E, or from c on the buccal side to a point 
opposite on the lingual. This cavity, being a compound one, must have 
added together for its length, the floor of the step d, the axial wall F, and 
the floor a. The depth of the lingual and buccal walls is seen at c, and 
the depth of the floor at a. The axial wall and height of it is seen at 
F, and the floor of the step at D. 



Fig. 247 



Fig. 248 



Fig. 249 




Cavity preparation of a molar 
for the matrix. 




E 
A B 

Cavity preparation, showing square 




Section of molar, 
showing the introduc- 
tion of the cushion. 



In Fig. 247 is represented the cavity preparation, with which, in 
connection with the matrix and soft and cohesive gold, the operator is 
enabled to bring gold work in cavities of this class to a degree of per- 
fection rarely approximated without its aid. 

At the cervical margin of Figs. 247 and 248 it will be observed that 
the floor of this aspect of the cavity, a, and the external wall of the 
tooth, B, form practically right angles, which is the angle, all things 
considered, with which to secure the best margins and best results. 

Beginning well up on the side wall at c, Fig. 247, passing down and 
along the base of the cement step and up the opposite wall, is a groove, 
c, better shown in the sectional cut, Fig. 249, made with a No. 3 or 4 
round bur, or Darby-Perry excavator, Nos. 11 and 12, designed as an 
anchorage for the base of the cervico-occlusal column, marked non- 
cohesive gold, Fig. 251. In this groove, which should be shallow and 



CAVITY PREPARATION FOR MATRIX WORK 



241 



upon the floor surface, a, is condensed the gold. The groove extending 
up the side wall is not a necessity, though it may be incorporated in the 
cavity formation when the walls are strong, but that portion of it along 
the floor should be employed. 

In the instances where the lateral walls are weak and the groove 
cannot be formed, the occlusal anchorage shown at d, Figs. 247 and 248, 
should be employed. In the formation of the side-wall edges, e e, Fig. 
248, care must be taken to leave them strong enough to prevent fracture 
under the pressure of the matrix band. These walls should be bevelled 
on the lines E E, Fig. 248, terminating in an obtuse angle with the external 
surface of the tooth, if practicable. Less than a right angle should 
not be depended on, if it can be avoided, as there is danger of fracture. 



Fig. 250 



Fig. 251 



Fig. 252 




■di--B 



D 



Cavity preparation, showing 
subdivisions of filling. 




COHESIVE GOLD. 

CEMENT. 
NON COHESIVE GOLD. 



Section showing the plan 
of a matrix filling. 




Section showing 
the condensation 
of cushion A' of 
Fig. 249. 



In the formation of the cavity in Fig. 247, with the rounded corner 

c, is seen the preparation suitable for amalgam or other plastic materials 
in connection with the matrix; and for cushions and cylinders of foil if 
the cavity approximates the form seen in Fig. 248, and at F and H of 
Fig. 252. But these corners should be modified as nearly as possible 
into the form seen at n n, Fig. 248, if the cavity is shallower from a to 

d, Fig. 248, than from f to h, Fig. 252. 

The square corners aid in better locking and binding the foundation 
subdivisions in the process of building in the filling (see Fig. 250). 

But when the cavity assumes the proportions seen at f to h, Fig. 252, 
the matter of square corners is not necessary, because when the distance 
from the top of the step, Fig. 252, to the floor is greater than from F on 
the axial wall to h on the matrix band, we have a form of cavity in which 
the cushions and cylinders bind and hold without the aid of square 
corners. 

It should be a rule of practice to put in cement steps whenever the dis- 
tance from the axial wall to the matrix band is greater than from the top 
of the step to the floor of the cavity, and bring the form of the cavity as 
nearly as possible into that shown in Figs. 249, 252, 253, and 255; be- 
cause, first, it necessitates the use of less metal, whether of gold or tin; 
16 



242 USE OF THE MATRIX IN FILLING OPERATIONS 

second, it is better when finished, and more quickly filled to the top of 
the step (Fig. 253); and third, it avoids the formation of the square 
corners, N N, Fig. 248, extending so deeply toward the pulp as to weaken 
the walls of the tooth. 

In the introduction of the filling into the corners of Fig. 248, the 
method suggested is to carry in the cushion of soft gold or tin, as the 
case may be, and place in the corner at a with pluggers, Nos. 257, 258, 
or 259, Fig. 291, whatever size of these forms shall best suit the case, 
and partially condense it. In the opposite corner place in the subdivi- 
sion B, and then the subdivision c. Only this last introduction is carried 
straight down in the direction of the long axis of the tooth, while the 
other subdivisions, as seen in Fig. 250, are placed in diagonally and 
compressed in place. At this juncture hold down with a suitably shaped 
instrument, No. 174 or 175, Fig 291, on one side and condense the other 
with the automatic mallet carrying a suitably shaped plugger, No. 18, 
Fig. 291, until adequately condensed. After this, change instruments 

Fig. 254 






Section showing cervico-oc- Section of pulpless molar Section showing the recon- 

clusal wall built to top of step. before placing in the cement struction of pulpless molar 

G, groove for the grasp of the step. with cement step, 
capping slab. 

about, and treat the opposite side in a similar manner. If the cushions 
are proportioned properly to the size of the cavity, two sets of each of these 
put into subdivisions a, b, and c, Fig. 250, will bring the wall to the 
top of the step, or nearly so. 

Fig. 247 represents the preparation of decay cavities, whether appear- 
ing on bicuspids or molars, the outer outline of wliich appears in Fig. 
256 and comes under the head of the major class. All such decays 
should as nearly as practicable be prepared after the suggestions of 
Fig. 247. 

In the formation of the cavity in Fig. 247, when the tooth is normal 
and its functions comfortably performed, care must be exercised to avoid 
too near approach to the pulp, particularly when the cavity is located in 
bicuspids, in which case we have a shallower zone in which to work than 
is found in the corresponding parts of molars. In the deeper cavities of 
bicuspids and molars, zinc phosphate should be used to bring the cavity 
into simple form, as seen in Figs. 251, 254, and 255. 



CAVITY PREPARATION FOR MATRIX WORK 243 

When these cavities are prepared after the suggestions and illustra- 
tions of the figures referred to and embraced by the matrix, not only is 
less material needed to bring up the cervico-occlusal wall to the top of the 
step, but additional advantages are gained in that the cavity is simpli- 
fied, the filling rendered easy of execution, and the character of the work 
improved. 

Oxyphosphate of copper cement, being more adhesive and less a 
thermal conductor, and possessing more of antiseptic property than the 
other forms of zinc cements, should be employed wherever practicable 
for step making. Its inky blackness perhaps is against its use in the 
anterior teeth, and farther forward than the molars. But it is also less 
irritant and is harder and stronger than any of the zinc phosphates. 
So that, in the instances where the cavity penetrates to or beyond the 
pulp, and compels the formation of a cavity as deep from the matrix 
band to the axial wall, as is shown in the pulpless tooth, Fig. 254, or as 
already cited, when the depth of the cavity from f to H, Fig. 252, is 
greater than the height of the step, the cement should be placed in posi- 
tion to bring the axial wall close enough to the matrix band to form the 
cavity into the proportions shown in Figs. 249, 252, and 253 when em- 
braced by the matrix. 

This class of cavities, when filled with gold, should be filled with soft 
gold cushions or cylinders to the top of the step D, Figs. 247 and 248, 
when, after forming the groove shown at G, Figs. 251 and 253, should 
be completed with cohesive gold and built securely in place. The 
anchorage, Figs. 247, 248, and 250, at D, indicate what this should be. 

The procedure in the introduction of the soft-gold part, or of tin when 
that is used, in the major class, is seen at k, Fig. 249, and when con- 
densed, at L, Fig. 252. The introduction is in the direction of the long 
axis of the tooth and not diagonal, as shown in Fig. 250, although the 
diagonal introduction may be employed in special cases favoring it. 
The cushions thus introduced, rarely less in size and bulk than a size 3 
cylinder, and generally much larger, do not fill up squarely out to their 
ends or to the lateral walls; and the operator must look to these points, 
and level them up with small cylinders or their equivalent in cushions. 

The final condensing of this column as seen at I, Fig. 253, and before 
the cohesive part is begun, should be done by holding down the gold 
at one side of the cavity, while the automatic mallet condenses at the 
opposite, as suggested in the filling of the cavity of Fig. 248. The 
student must appreciate the importance of condensing first the soft gold 
at n, and afterward the cohesive at e, Fig. 248, when that figure is em- 
braced by the matrix. Pluggers Nos. 7 or 8, Fig. 291, of small treading 
surface, are suitable for doing this part of the work. The cohesive gold 
should be used in narrow strips when the angle into which it must go is 
close and sharp. 

It is the purpose in engineering construction to secure the greatest 



244 USE OF THE MATRIX IN FILLING OPERATIONS 

possible strength from the arrangement of material entering into such 
construction. In the formation, therefore, of the anchorage for the fill- 
ings of the major class of the cervico-occlusal cavities, due regard must 
be given to the proportion of gold and enamel in making the anchorage 
head in the occlusal surface of fillings of this class. 

Just as it is possible to weaken a carriage wheel by having the tenons 
of the spokes so large as to weaken the hub, it is also possible to have 
the tenons so small and the hub so strong as from this cause to weaken 
the wheel. So also with the anchorage of this class of fillings; the neck 
of gold going into the head of the anchorage may be so small, narrow, 
and shallow that the stress of chewing will cause it to break at this point. 
And yet the neck may be widened and deepened so much that the gold 
becomes stronger than is necessary, and the enamel on either side becomes 
correspondingly weak, and gives way under stress of mastication. 

The problem then is to proportion the neck of gold and the enamel so 
as to secure the greatest strength. 

Assuming the depth of the gold neck to be about its width, the rule 
of one-third gold in width and two-thirds enamel, one third each side 
of the gold, answers the requirement. 



THE MINOR CLASS 

While the principles inculcated by Drs. Webb, Black and others in 
extension for prevention — extending the cavity margins well away from 
the contact point of the teeth — hold good in the larger proportion of cases, 
there are those individual instances presenting when the operator will not 

Fig. 256 Fig. 257 Fig. 258 





Bicuspid, showing the Side view, showing the outline of the Transaxial section, show- 

major and minor class major and minor preparation. ing anchorage of the minor 

cavity outline. class at line A of Fig. 257. 

be justified in employing extension for prevention. Take, for instance, 
the highly developed teeth, with perfectly fused enamel through the 
sulci dividing the cones, lobes, and cusps of the molars and bicuspids, 
which from the excellence of their quality and the cleanliness of the 
patient almost entirely prevent caries; it would be unwise and unneces- 
sary under these conditions to extend in preparation the borders of these 
cavities to the extent taught and endorsed in extension for prevention, and 
yet so necessary in many of the larger decays denominated the major 
class. 



THE MINOR CLASS 245 

The preparation of the minor class of decays, represented in the inner 
outline of Fig. 256, should be formed after the suggestions of Figs. 257, 
258, and 259. The student should comprehend the formation of both 
the major and minor class, as each must be prepared according to the 
suggestions made. 

The preparation, therefore, for the minor class may be enlarged to the 
proportions shown in the inner outline of Fig. 257, while the outer out- 
line of Figs. 257 and 259 would show the formation of the major class 
on the same tooth. 

Fig. 260 is a sectional cut showing the completed major class of the 
cervico-occlusal fillings, as adapted to and completed in the bicuspid. 

Fig. 258 is a transaxial section at the line a on Fig. 257; and at this 
point the anchorage for the minor class is seen in Fig. 258. The anchor- 
age can and should be made strong here under the buccal lobes of bicus- 
pids and molars, and similarly at the lingual sides. Above the anchor- 
age, toward the occlusal surface, the cavity should be so modified as to 
come out on the occlusal surface, as shown in Fig. 259. 

Fig. 259 Fig. 260 Fig. 261 






End view, showing out- Section showing the com- M , 2-grain cube of gold, 

line of major and minor pleted major class filling on showing relative size to the 

cavity preparation. bicuspid. cavity in which it rests. 

The pluggers, Nos. 115 and 116 or 117 and 118, Fig. 291 — pairs in 
two sizes — are invaluable for tacking the cohesive gold into the condensed 
soft gold. Much of this part of the work must be done by hand pressure; 
and it is important, in view of this fact, to prepare the gold in narrow 
strips, which should be annealed with electric heat to insure the strongest 
cohesion. 

In the filling of this class of cavities the matrix should be applied, 
and soft gold brought up to the anchorage shown in Fig. 258. At this 
point cohesive gold should be thoroughly condensed into the anchorages, 
and brought out, finishing the contour of the tooth. Care should be 
taken to bevel somewhat the occlusal surface of this filling to prevent the 
too positive impinging of the occluding tooth in the opposite jaw. 

The beginning of the cohesive on the condensed soft gold and the 
fastening of it there, in whatever class of cavities, depends on careful 
attention to several details: First, the operator must so conduct his 
operation as to control the saliva perfectly, keeping his work dry. Second, 



246 USE OF THE MATRIX IN FILLING OPERATIONS 

the matrix must be fixed and rigid in its application. Third, the pluggers 
should be kept freshly serrated, and of such forms as give direct entrance 
to and application of them at the point on the work. Fourth, the serra- 
tions should be clean and deep. Fifth, the gold should be clean, and 
freshly annealed. Any of the forms of cohesive gold may be used if 
the portions carried each time to their destination are small, clean, and 
annealed. Small cohesive gold cylinders, Nos. J and J, are easily used 
for this work, and the smaller ones should not only be employed to 
begin with, when this form is used, but as far as practicable throughout. 
The strips or ribbons, however, of cohesive gold when freshly annealed, 
and with all other conditions above enumerated complied with, give best 
results. The ribbon is tacked or pricked into the soft gold by interdigita- 
tion, and the union made with this or any preparation of cohesive gold 
while not strong, is enough so to enable the operator to reach his anchor- 
age points, where he may thoroughly secure the work. 

In making matrix fillings, if the matrix employed is of the band or 
loop variety and has no separating feature, in order to secure contour, 
and to have the fillings finished in the original form of the tooth, the 
teeth, if two are together, should have the cavities previously packed with 
cotton, long enough to produce mobility of them, so that they may more 
easily yield apart. This then gives opportunity to push the teeth apart 
still farther, especially with those matrices provided with the separating 
feature, and so to gain room in which to shape the matrix band and to 
reproduce the contour of the tooth. 



PREPARATION OF GOLD FOR MATRIX WORK 

In the soft-gold part of matrix work the form of the gold to be em- 
ployed is important to be understood. Large cylinders and cushions in 
comparison with those ordinarily used in cavities of given size are not 
only more safely and perfectly adapted, but more quickly done. This 
results from doubling and partly compressing the cushions, which, being 
further susceptible of compression, are still large enough to squeeze in 
place and bind as they are compressed. 

In placing cushions into the bottom of large cervico-occlusal cavities 
of molars and bicuspids embraced by the matrix, it is important to start 
with those of sufficient size and density to bind as they are condensed, 
but it is not to be understood that the first such piece introduced must be 
fully condensed before other similar pieces are added. If this practice 
were followed, notwithstanding the fact that the first piece introduced 
binds as it is condensed, this is so only to a certain point of the conden- 
sation. Beyond this, if we continue it, especially to that density which 
may be obtained against the resistance the tooth affords, it loosens, will 
tilt and rock, and is worthless. But if after placing in one cushion, 



PREPARATION OF GOLD FOR MATRIX WORK 247 

which the operator learns to proportion to the size of the cavity, and 
partially condensing it, he introduces another and carries the conden- 
sation to the point of the first, and still another, he may then mallet until 
the mass will yield no more; and the wall of soft gold thus built will be 
steady, well adapted, moisture proof, and impervious to leaking by 
capillary force. This comes of the fact that when three or more cushions 
or cylinders are carried down as described, the bearing up and down the 
axial and matrix walls is sufficient to insure binding and steadiness. 

In the illustration, Fig. 249, will be observed at k a gold cushion 
entering the cavity between the axial wall f and the matrix band H. 
The cushion is made of one-half of the gold twist shown at Fig. 262, 
and contains two grains of gold by weight. This cushion, when con- 
densed to its ultimate density, as by melting and hammering, is repre- 
sented in cube form and exact size at M, Fig. 261. 

Fig. 262 



Leaf of No. 4 gold foil, twisted ready for formation into cushions. 

A No. 4 gold cylinder, as made by the manufacturer, one-fourth of an 
inch long, contains one grain of gold by weight, and when this is con- 
densed into cubic form it is one-half the bulk of the cube shown at m, 
Fig. 261. It transpires then that the large loosely made No. 4 cylinders of 
one grain weight are more difficult of satisfactory adaptation than those 
which contain the two or more grains, because the large loose ones lack 
the bulk and substance which is necessary to cause them to bind and 
fasten in condensing. 

It will be seen further, by comparison of the 2-grain cube M, Fig. 
261, with the proportions of the cavity in which it rests, that it reaches 
hardly half across the cavity, bucco-lingually, and that if this cube were 
elongated so as to reach across the cavity, its bearing against the axial 
wall and the matrix band would be lowered at least one-half, and there 
would not be sufficient bearing up and down these walls to hold the gold 
fixedly in place. This then demonstrates the difficulty of adapting gold 
or tin foil at such points with cylinders or cushions containing less than 
enough material to bind and hold the mass in place in the process of con- 
densing. And if this be true, as is illustrated in Fig. 261, it is seen that 
the size 4 cylinder, containing only one grain, would be still more difficult 
to control, because it lacks in greater degree the bulk and substance 
sufficient to give the bearing up and down the walls necessary to the 
binding and fastening in the process of condensing. Neither will the 
cylinders or cushions containing two grains or more in very large cavi- 
ties bear complete condensing, before adding other pieces without loosen- 
ing, for the reasons already given. In exceptionally large cavities of the 
major class, a sheet of No. 4 foil may be formed into a single cushion, 



248 USE OF THE MATRIX IN FILLING OPERATIONS 

and introduced to advantage. Such a cushion containing four grains 
would not build higher than is necessary to bind, even if it were formed 
into a rectangular parallelepiped — two cubes side by side, and extending 
from one lateral wall to the other. 

The successful making of fillings with either gold or tin is not so 
much a question of securing the ultimate density of these materials, as 
that of securing adaptation of them to the walls of the cavity in such 
manner as shall prevent leakage beneath, in, and around the filling. This 
result may be obtained with a compression or condensation of much 
less density than is shown in the melting of them, or as is obtainable 
against the resistance which the tooth offers. 



FORMATION OF CUSHIONS FROM FOIL 

The cushion of either gold or tin, rather than the cylinder, is a better 
preparation for matrix work, even when it is made from cylinders com- 
pressed or doubled upon themselves, because the cushion, made of foil, 
while soft enough to be adapted to the irregularities of the cavity, contains 
from twice to four times the amount of material which the loose cylinders 
do, and because of this fact, in connection with proper handling and 
cavity formation, they are more easily secured in place. 

The student should appreciate the fact that until he succeeds in laying 
the foundation of soft-gold work in a manner to prevent its moving or 
shifting position in the process of condensing, he will have failed to 
secure the results within his reach. The employment of the cushion, 
therefore, rather than the cylinder, is urged as the best means to this 
end. 

The formation of cushions from the foil is as follows: Take a full 
leaf of No. 4 soft gold foil, and with clean hands crimple and wrinkle 
it. Straighten this out, but leave the sheet undulated, when it should 
be loosely folded three to four times upon itself and loosely twisted. The 
twist thus made should be cut into from three to five pieces, Fig. 262, 
depending on the size of the cavity to be filled. The large cavities, 
such as are seen in the proximal surfaces of molars, Figs. 247 and 
248, will take a cushion made from the longer section of the twist shown 
in Fig. 262, which may represent one-half or more of the sheet of No. 4 
foil; while cavities of the proportions shown in Fig. 257 will take one- 
fourth or less. Smaller proximal cavities in the incisors will take from 
one-fifth to one-third of a half-sheet prepared after the manner of Fig. 
262. The cushions prepared after these suggestions, when used for the 
large cavities of the molars and bicuspids, should somewhat resemble the 
illustration in Fig. 263. The preparation thus made is more desirable 
than the cylinders made of soft foil, because it is more easily manip- 
ulated and with better results, and because the student learning to do 



M 



FINISHING THE FILLING 249 

this secures to himself a resource which enables him to prepare his 
cushions for all sizes of cavities, and is never at a loss for what is wanted 
when foil is to be had. 

But when this class of work is to be done with tin foil, the cylinders, 
compressed or doubled, will serve best, since it is difficult to obtain a foil 
of tin light enough and soft enough to make desirable cushions. 

Fig. 263 



Cushion formed from twisted leaf of Fig. 262, or from partially compressed cylinders. 

Tin foil in cushions, made by doubling the cylinders upon themselves 
for the foundation portion of cervico-occlusal fillings, in connection with 
the matrix, and under the finishing slab of cohesive gold, works even 
more kindly, and adapts more easily than cushions made from soft 
gold foil; and if its use here is not forbidden by electrolysis, it is to be 
given first place as a tooth preserver at the cervical margins, and as a 
non-conductor of the thermal changes to the pulp. Tin foil and soft 
gold foil laid together, and the two formed into cushions after the sug- 
gestions already made, may be used with results quite as beneficial for 
preservation of the margins embraced by the matrix as when gold or tin 
alone is used, with the advantage of avoiding the danger of electrolysis of 
tin under gold. 

FINISHING THE FILLING 

No part of the work of making gold fillings, such as are included in 
the major class particularly, is more laborious than the finishing of them. 
Yet when the matrix has been properly adapted to the teeth, the finishing 
of the cohesive gold part may be lessened to the minimum. 

The more rapid and satisfactory finishing of the work following the 
use of the matrix is no small part of the advantage of this device, since 
the matrix gives not only the form of the wall which it embraces, but 
more than any other method yet devised saves filling material. This 
comes of the fact than when it is properly adjusted the cavity is converted 
into a mould so nearly the shape of the filling to be, that when it has 
been made very little work remains to be done in polishing. 

The first step toward polishing after removing the matrix is to go 
around the borders of the soft-gold portion of the filling with a blade 
burnisher, which should be kept highly polished and clean. In this 
operation the object should be to compress as much as possible by hand 
pressure the soft-gold portion that may have bulged under the malleting. 
After this the Rhein trimmers, Nos. 31 and 32, should go over the 



250 USE OF THE MATRIX IN FILLING OPERATIONS 

borders, and should be held so that the blade shall rest equally on the 
filling and the adjacent external surface of the tooth. 

At this point, if the operation is between molars or bicuspids, the 
Perry separator is valuable, and should be placed so as to have the beaks 
impinge above the margin of the filling, and should be made to open 
the teeth only enough to pass in the thinnest strips and sandpaper disks. 
Care and skill are required in the handling of disks to avoid grinding 
away the contour of the filling, but the disk can be so held as to prevent 
this. 

The author finds, in removing the overhanging corners of the cohe- 
sive portion of these fillings, that the use of a stiff five-eighths inch garnet 
disk, held only to the corners and not permitted to pass in between the 
teeth, answers better than any form of corundum or carborundum 
wheels. 

After thus carefully shaping the cap or slab of cohesive gold at the 
contact points, and rounding them as the case permits and requires, flint 
strips and the "regular" grit, followed with the "fine" cuttlefish disk, 
completes the polish. 

The occlusal surface of cohesive gold is easily shaped with corundum 
wheels and polished with the cuttlefish disk, when these can be made to 
apply, or with leather wheels carrying pumice. 

There is no essential difference in polishing the major and minor class 
of these fillings, except in the extent of the work. 



FORMS OF MATRICES FOR MOLARS AND BICUSPIDS 

A presentation of all the devices known as matrices is not the purpose 
of this chapter, but only of those whose efficiency commends them. 

Fig. 264 represents the set of matrices devised by Dr. Louis Jack. 
This set of matrices is provided with concave surfaces for contouring the 
teeth, which indicates the high ideal of the originator of the device. 
They are made thick and heavy at the base of the lateral edges, which 
aids in steadying them between the teeth, and they are provided with 
slotted edges, which engage a special pliers to insert and remove. 

Fig. 265 shows a set of loop matrices, which at times, and with teeth 
of slight constriction at the neck, answer well; but, like all of the loop 
variety, they require space at both sides of the tooth to admit of adjust- 
ment. 

Fig. 266 exhibits a set of matrices devised by Dr. Truman W. Brophy, 
which, with the flexibility of the thin steel bands and under the action 
of the screw, may be made to aid the operator most acceptably. 

The band is not unlike the loop in the matter of passing between the 
teeth, and the teeth must yield apart to admit it. Still, with the thinness 
of the bands in this set, there is no difficulty in this particular. 



FORMS OF MATRICES FOR MOLARS AND BICUSPIDS 251 

This form of matrix, however, is unsteady and difficult to fix rigidly 
on very short crowns, and particularly on those of decided conicalitv. 

Fig. 267 exhibits an improved loop matrix devised by Dr. S. H. 
Guilford, in which the lip feature is added for the purpose of having the 
band to catch below the cavity, without the necessity of forcing the band 



Fig. 264 



IHI9E SJHs *5j 

The matrices of Dr. Louis Jack. 
Fig. 265 




C 



@) 




Loop matrices. 
Fig. 266 




Brophy's band matrices. 

elsewhere around the tooth into the gum. This device, made in several 
lengths of bands, although tedious to adjust, from the fact that three 
pieces must be handled, is otherwise valuable and serviceable. 

Fig. 268 illustrates Dr. W. A. Woodward's screw matrices. This 
form of matrix has valuable features in that the thin metallic ribbon 
constituting the matrix wall may be made as thin as Xo. 36 to 38 gauge, 
and yet possesses adequate tensile strength. The device is also valuable 
because in its use only one thickness of the ribbon need be carried 



252 



USE OF THE MATRIX IN FILLING OPERATIONS 



between the teeth. Again, it has the separating feature, which makes it 
additionally desirable, as this forces apart the teeth to start with, and the 
separation is continued as the operation proceeds, or as the exigency of 
the case demands. 

Fig. 269 shows illustrations of Dr. E. B. Lodge's matrix bands, ten- 
sion screws, and wrench. Those marked a are adapted to bicuspids and 
molars of usual form, while those marked B are adapted to the same class 
of teeth, but of constricted necks and more pronounced bell-shaped 
crowns, c and d of this illustration show two forms of tension screws, 
and f and e the wrench for operating the screw d. Fig. 270 shows the 
Lodge device adjusted to the teeth. 



Fig. 267 




Guilford's band matrices and clamps. 
Fig. 268 




Woodward's screw matrices. 

The bands of the Lodge matrix are made of German silver, and are 
provided with two eyelets in each, giving ample range of adjustment. 

Figs. 271 and 272 show a form of matrix suggested by Dr. A. C. 
Hewett, which for simplicity and efficiency meets a constantly occurring 
want. In the instances where the matrix is employed between the teeth 
and it is braced by an adjacent tooth, and where no straining apart of the 
teeth is required, this device is admissible. But it should be braced with 
a wedge, ordinarilv at the cervical edge. 



- 



FORMS OF MATRICES FOR MOLARS AND BICUSPIDS 253 

Fig. 273 is a form of matrix which has been used by the author in 
extensive cavities occurring on the buccal surfaces of lower molars. 



Fig. 269 




■Jmrnfflfflti^ 




Lodge's system of loop matrices. 



Fig. 270 




The Lodge matrix in position on the teeth. 



Fig. 271 



Fig. 272 



The Hewett matrix held in position 
with the Parmly Brown clamp. 



Fig. 273 




The Hewett matrix held in The band matrix 

position with the ordinary used in extensive 
rubber-dam clamp. buccal surface cavi- 

ties on lower molars. 



The band which must be fitted to each case is made from No. 35 to 
36 gauge German silver, and so cut that the projecting arms turned down 



254 USE OF THE MATRIX IN FILLING OPERATIONS 

on the occlusal surface of the tooth prevent it from carrying down with 
the wedge as the device is tightened. In the instances where the cavity 
extends beneath the gum the band can be provided with a lip to catch 
below the buccal margin. The dam can rarely be employed in these 
operations, but fortunately it is not necessary for the first part of this 
operation. 

When the lingual and buccal sides of these teeth are provided with ab- 
sorbent-cotton rolls, and especially when the saliva ejector is employed, 
the cavity may easily be filled to the top of the band with soft gold 
or tin, as suggested elsewhere in this chapter, before moisture shall 
interfere. 

If the capping for this filling shall be of amalgam, it may be finished 
within the time that the absorbents protect. If the purpose is to finish 
with gold, the dam should at this juncture be placed over the band and 
tooth after the soft-gold part is brought to the top of the band, and the 
remainder of the work finished with cohesive gold. 

Fig. 274 Fig. 275 



OOOO 




The Hodson contour slip matrices. The Hodson matrix in position between 

the teeth. 

Fig. 274 represents the contour slip matrices devised by Dr. J. F. P. 
Hodson. The device is a most meritorious one, with which the contour 
of molars and bicuspids can be fully restored, but can only be used 
between the teeth. Fig. 274 gives two views of the matrix ready to be 
slipped in place. 

These matrices are made preferably of thin annealed steel plate, forged 
or swaged on a leaden slab with an oval-end punch, giving them what- 
ever of concavity the case may require; they are then slipped in place, 
which causes the teeth to yield apart. The gingival end of the device 
should be braced against the adjacent tooth with an orange- wood wedge 
until after the filling is inserted. 

The Hodson device is better adapted to amalgam work than gold, be- 
cause it does not possess the rigid fixedness in sufficient degree to remain 
securely in place for extensive gold operations. 

If the filling material used is a plastic the device is left in place over 
night or longer, allowing the filling to set under pressure, which may be 
done readily, as the device shown in Fig. 275 is in no wise uncomfortable 
or troublesome to the wearer. 

When the adjustment of the matrix is properly made, it is unneces- 
sary in most instances, particularly in the upper jaw, to use the dam. 



FORMS OF MATRICES FOR MOLARS AND BICUSPIDS 255 

Fig. 276 represents the contour matrix as devised by the author of 
this chapter. This device, which is of duplex form, is only used between 
the teeth, and acts in the three-fold capacity of matrix, separator, and 
rubber-dam clamp. The device is shown in position between two 
molars, the cavities of which have been prepared after the suggestions 
of Figs. 247, 248, and 249, and the manner of introducing the cushion. 
With this form of matrix the teeth may be drawn apart as with the sep- 
arator, and the fillings given the contour the teeth originally possessed. 



Fig. 271 




Fig. 277 




The Crenshaw contour matrix in position 
between molars. 



The contour matrix with one band turned 
out for removal. 



Fig. 277 shows the method of removing the matrix, as may be done 
when amalgam is used without lifting or unseating the filling. To do 
this the pin is withdrawn and the band embracing the unfilled tooth is 
turned out on the tension screw as a pivot. After this the band em- 
bracing the filled tooth is lifted away from it, when the matrix may be 
removed from between the teeth. In amalgam work with this device 
only one tooth should be filled at a sitting, and after this filling has crys- 
tallized and become fixed in the tooth the second one should be made. 



Fig. 27 



Fig. 279 







The contour matrix holding absorbent 
cotton in position. 



The contour matrix in position between 
bicuspids. 



Fig. 278 shows how the operator may protect his work without the 
dam in the lower jaw by placing absorbent-cotton rolls on each side of 
the teeth, and how these are held in place by the matrix. The employ- 
ment of the cotton rolls gives time in which to insert amalgam and other 
plastic fillings before the rolls become saturated with saliva. In the same 



256 



USE OF THE MATRIX IN FILLING OPERATIONS 



manner the cervico-oeclusal columns of these fillings may he made of 
gold or tin cushions to the top of the step with the aid of the rolls and 
the saliva ejector, when the matrix should be removed, the dam put over 
the teeth, the matrix reapplied, and the operation finished with cohesive 
gold. 

Fig. 280 Fig. 281 

D 





The contour matrix in position be- 
tween canine and first bicuspid, with 
bow brace attached. 



Enlarged figure of the anterior teeth matrix: A and B, 
arms; C, projection screw; D, metallic ribbon. 



Fig. 279 shows the application of the short-bar matrix as adapted to 
bicuspids and between canines and first bicuspids. The bicuspid device 
is better adapted for use between molar and bicuspid than the molar one, 
although the latter may be employed at these points. 

Fig. 280 shows the contour matrix in position between a canine and 
first bicuspid, in connection with the bow brace, which prevents the 
matrix slipping from between the teeth, as it is inclined to do on account 
of the bevel of the lingual side of the canine. 



MATRIX FOR THE ANTERIOR TEETH 



In the effort to improve gold work in the proximal cavities of the 
anterior teeth by a method which practically does away with cohesive 
gold, the author offers the anterior teeth device. 

Fig. 281 shows the device enlarged, as it appears before being placed 
in position about the teeth, and with the lower part shown in section. 
The arms at a and b project through the loops formed on the ends of the 
metallic ribbon d, the thickness of which is toVo of an inch, and which 
may be passed between teeth of rigid contact. The parts a and b are 
separable, and when the tension screw c is turned in, the arm B is ex- 
tended, which puts the ribbon d under tension. 

Fig. 282 shows a lingual view of four incisors with the matrix ribbon 
in position before it has been adapted at the incisal edge. Fig. 283 shows 
the ribbon crimped and soldered, which adapts it closely to the tooth 
at the incisal edge, and to the surface of the tooth beneath the ribbon. 

Fig. 284 presents a labial view with the device in position, and shows 
how cavities which extend through and open on the lingual face of the 
tooth may be floored and brought into simple form. 



MATRIX FOR THE ANTERIOR TEETH 



257 



Fig. 285 shows a means of taking up slack in the ribbon, if this should 
become necessary, by slipping the slitted arm astride of the ribbon, as 
shown in this figure. By this means, if at any time the tension screw 
should be run in to its limit, additional tension can be obtained without 
removing the ribbon. 



Tig. 282 



Fig. 283 





The metallic ribbon in position before 
crimping. 

Fig. 284 



The metallic ribbon adapted to tooth after 
crimping. 

Fig. 285 





The holder applied for tensioning the ribbon. 



The holder applied for taking up slack in 
the ribbon. 



Fig. 286 



Fig. 287 





Application of the ribbon pressing the left 
central forward. 



Application of the metallic ribbon between 
the anterior lower teeth. 



Fig. 288 



Fig. 289 




Application of the holder pressing the lower 
right central forward. 




E, cervical, F, incisal, G, Ungual, H, labial 
subdivision of proximal incisor filling. 



Fig. 286 is a view showing the cutting edge of the teeth and the crimp 
of the metallic ribbon. 

Fig. 287 is an application of the ribbon to the lower incisors. It must 
ordinarily be placed between the teeth before applying the holder. Fig. 
288 shows the holder in position, 
17 



258 USE OF THE MATRIX IN FILLING OPERATIONS 



FILLING PROXIMAL CAVITIES WITH COHESIVE AND NON- 
COHESIVE GOLD WITH ANTERIOR TEETH MATRIX 

Fig. 289 shows a proximal cavity in a central incisor three-fourths 
filled by the aid of the matrix, after which the matrix is removed. The 
subdivisions of the filling, lettered e, f, and G, are made of soft gold, 
leaving the space marked H to be filled with cohesive gold. The pro- 
cedure which best accomplishes this is as follows : If the cavity be a large 
one, take a No. 3 or 4 soft-gold cylinder and double it upon itself and 
again crosswise, making a firm cushion. Let this cushion be large 
enough to squeeze into place. Take a foot-shaped plugger with light 
serrations, Nos. 257, 258, or 259, Fig. 291 — whatever size of this form 
best suits the case — and press this first cushion into the undercuts of the 
cavity at e. After settling it by hand pressure, take a suitable foot- 
shaped plugger, No. 257 or 258 answers well, in the automatic mallet, 
and, while holding down at the lingual side of the cushion, mallet the 
other, after which change the instruments about, and mallet the labial 
side. After this is done, treat the opposite end of the cavity at F in the 
same way, only the cushion going into this subdivision may occasionally 
have to be drawn into place with the throat of the instrument. When 
the f subdivision is condensed, use a No. 2 cylinder folded once upon 
itself, and introduce end-wise at G, which when condensed keys E and F 
in place. If the cavity be a large one it will require two of the No. 2 
cylinders, and in some cases three, to bring this part of the filling to the 
centre of the cavity, which is necessary in order to securely brace E and 
F in place. 

The author cautions against using small soft cylinders with which to 
make a key-block, because when condensed they do not build up high 
enough to obtain the necessary lateral bearing against blocks E and F to 
hold firmly in place. Neither should cohesive gold in any form be used 
here. 

It will be observed from the lines of the cavity division in Fig. 289 
that the cavity is to be filled from the labial side, and that it extends 
through into the lingual face of the tooth, also that the matrix ribbon, 
which has been removed to show the plan of the filling, envelops and 
embraces the tooth in such manner as to floor the lingual portion of the 
cavity, as may be seen in Figs. 284, 285, 287, and 288. 

The action of the device not only moves the tooth forward to be filled 
as seen in Fig. 286, so that it may be got at easily, but transforms a dif- 
ficult cavity into one of easy, simple form. 

In the instances where the opening of the cavity is toward the lingual 
aspect with a labial wall to be preserved, the device operates with as 
much favor in filling from the lingual as from the labial aspect — see 
Figs, 283 and 286. In these figures the action of the device will be 



P LUGGERS FOP, MATRIX WORK 259 

seen to move forward the left central and depress the right central and 
left lateral. 

When the filling is made from the lingual aspect, the lines of the sub- 
divisions of the filling, Fig. 289, would be reversed, and the key-block 
H would be placed in the position of G. 

PLUGGERS FOR MATRIX WORK 

The point of a plugger is not all of its efficiency. The handle may 
materially enhance or handicap its performance, and the average student, 
unless guided in the selection of points and handles, is apt to get together 
in the selection of excavators and pluggers an incongruous combination, 
much of which will prove unsuited and unfitted for anything he is called 
on to do. 

Some of the forms of pluggers here suggested for matrix work may 
be found in the student's case. All included in the list of Fig. 291 are 
regarded as cohesive gold instruments, but several of these forms are ill 
adapted to that work and well adapted for soft gold. Many of the forms 
of instruments included in sets of soft gold pluggers cannot be utilized 
in the execution of the soft-gold part of the matrix fillings set forth in 
this chapter; and to assist the student in knowing which instruments 
shall be used to manipulate the cohesive, and which the soft, and the 
handles best suited to them, are pointed out and explanation of their 
uses made. 

The Handles Adapted to the Pluggers. 1 — Xos. 7,8, 10, IS, 115, 116, 117, 
118, 207, and 208 should be placed in cone-socket handles Nos. 4 or 5, 
Fig. 290, according as the shank of the plugger point is small or large. 
These handles can be used for hand pressure, but are designed especially 
for the hand mallet. 

Xos. 174, 175, 248, and 250 should be placed in the cone-socket 
handles Xos. 2 or 3, Fig. 290, according as the shank of the plugger 
point is small or large. 

Xos. 257, 258, and 259 should be placed in the rubber handles Xo. 10 
or 10a, Fig. 290, according as the shank of the plugger point is small 
or large. 

The Uses of the Several Pluggers.— Xos. 7, 8, 115, 116, 117, 118, and 207, 
Fig. 291, are for cohesive gold, and may be made to answer the needs of 
this work in connection with matrix fillings. 

Xo. 60 Parmly Brown plugger point, for cohesive gold, is of universal 
application, and is best used in the electric or the engine mallet. 

Nos. 174 and 175, Fig. 291, are assistant pluggers, used to hold down 
when malleting, and may be used for packing cushions in the cervico- 
occlusal column of molar and bicuspid matrix fillings. 

1 The handles, pluggers. and numbers of same are taken from the revised lists of the S. S. White 
Dental Manufacturing Company. 



260 



USE OF THE MATRIX IN FILLING OPERATIONS 



Nos. 248 and 250, Fig. 291 , are for soft gold, and used for placing and 
compressing the cushions into the subdivisions e and f, Fig. 289, of 
the smaller class of approximal incisor cavities. 



I? 



. ■ i : ■; ;>■ 



BOSOCCiOJ' 
B«C005SB« 

. : ■; ; ' - ; . c 



teas 

eetic:c«« 






U6k:3c« 






w 

■ 
lS9cee< 



tssssz 

•Hit) 

:cccc«( 
«iv:o» 

tc-ccco 
looooec 



*. — 

lttO0S» 
«S0C3«( 



fOflOCOCI 



Fig. 290 




3 4 5 10 

Handles for cone-socket points. 



10a 



Nos. 257, 258, and 259, Fig. 291, are for compressing the cushions 
into subdivisions e and f, Fig. 289, of the larger class of approximal 
incisor cavities. The square corners at the toe of these forms should be 
rounded oft. 



A MATRIX AUXILIARY 



261 



Nos. 10, 18, 208, 248, and 250, Fig. 291, are for settling and mallet- 
ing soft-gold cushions in the cervieo-occlusal column of molars and 
bicuspids (see Figs. 249, 252, and 253), and for carrying down and 
malleting the subdivision G, Fig. 289, and fillings of this class. 

A MATRIX AUXILIARY 

Dr. Alfred P. Lee, of Philadelphia, has devised a simple and practi- 
cable method of overcoming the difficulty often experienced in adapting 
the matrix to a proximo-occlusal cavity when the cervical portion of 
the missing wall presents a concave surface, due to the tendency of 
the roots to bifurcate. 

By the use of sheet copper, not more than xrnnr °f an mcn m thick- 
ness, in conjunction with the Ivory or similar matrix, an appliance is 
made which when removed after the filling has been inserted will be 
found to have kept the filling the desired shape, leaving no overhanging 
portions at the cervix to trim away. 



Fig. 292 



Fir;. 293 



Fig. 294 





Transverse section of tooth at 
a point near cervical border of 
cavity. Outer line showing cop- 
per matrix in position. Dotted 
line represents degree of contour 
supplied with hard wax or solder. 



Both matrices in position 
on tooth crown. 



Shows copper plate with 
cervical depression filled 
with soft solder and applied 
to cavity before adjustment 
of outer matrix. 



A piece of thoroughly annealed copper plate, large enough to cover 
the proximal portion of the cavity and extend, say one-eighth of an 
inch beyond the buccal and lingual margins, is pressed with cotton or 
bibulous paper pellets to conform to the concave root periphery at 
the cervix. The copper is then carefully removed and, if the cavity 
be for amalgam, the depression in the copper representing the cervical 
concavity is filled with hard wax until a convexity is obtained; the copper 
plate is then placed in position, and around it a steel matrix is adjusted, 
and when fully tightened the free edge of the copper is burnished against 
the steel. 

When gold is to be inserted it is necessary to use something more 
stable than the hard wax, therefore the concave surface at the cervical 
margin of the copper plate is touched with zinc chlorid, and over the 
alcohol or Bunsen flame soft solder is flowed into the depression. Any 
surplus may be trimmed off with a disk. 



CHAPTEE XI 

PLASTICS 

By MARCUS L. WARD, D.D.Sc. 
NATURE OF AMALGAM 

An amalgam is a combination of two or more metals, one of which 
is mercury, and may be either a liquid, solid, or semisolid. The term 
amalgam is derived from the Greek malagma, from mallasso, to soften, 
the presence of mercury lowering the melting point of such a mixture. 

The term " metal" indicates a certain number of chemical elements 
which in the present state of chemical science are undecomposable 
and possess certain well-defined characters in common, such as opacity, 
luster, conductivity, high specific gravity, and plasticity or capability of 
being drawn, squeezed, or hammered without loss of continuity. 

Comparatively few of the metals possess characters such as render 
them suitable to be employed alone by manufacturers, although there 
are many applications for most of them when two or more are caused 
permanently to unite. The compound thus formed by the union of two 
or more metals is termed an alloy. The word alloy is believed to be 
derived from the French aloi (the metal of the standard coin), a con- 
traction of a la hi (according to the law). An amalgam, then, represents 
that class of alloys which contain mercury. The agencies by which the 
union of metals is affected are heat, electrodeposition, pressure at ordin- 
ary temperatures, and by dissolving one or more metals which exist in 
a solid state at ordinary temperatures in a metal which exists in a liquid 
state at ordinary temperature. 

Practically all alloys, except dental amalgam alloys, are formed 
through the agency of heat, but certain soft metals, such as lead, tin, 
bismuth, cadmium, etc., have been shown by Professor Spring, of Liege, 
to form true alloys under pressure and absence of heat. This process, 
however, has not as yet found application much beyond the laboratories, 
where it is used to demonstrate that there is actual union between the 
particles of different metals in the cold when they are brought into 
intimate contact. Certain alloys, such as gold and copper, or copper 
and zinc, may be prepared by electrodeposition. Several alloys are 
prepared by this method on a large scale. 

The utility of dental amalgam alloys depends largely upon the property 
which mercury has of dissolving most other metals to the point of satu- 
ration, forming alloys which, when allowed to stand for some time, harden 
(262) 



NATURE OF AMALGAM 263 

or set. This hardening or setting process is probably due to the formation 
of a chemical compound between the mercury and one or more of the 
metals used in combination with it. The mass thus formed of metal or 
alloy in combination with mercury cannot be regarded, however, as a true 
amalgam, for Matthiessen has pointed out that such a mixture may be 
either a chemical compound, a solidified solution of one metal in another, 
a mechanical mixture, or a solidified solution or mixture of all three. 

There are some phenomena, such as change in volume, change in 
streno'th, and evolution of heat, that lead to the belief that definite com- 
pounds do exist in definite proportions by weight. Most of the metals 
used to form the alloy which is combined with mercury to form an amal- 
gam are capable of existing in a state of chemical combination, although 
they are subject to Matthiessen's classification, and are usually united by 
feeble affinities, for it is necessary, in order to produce energetic union, 
that the constituents exhibit much dissimilarity in properties. There is 
little doubt that these metals do unite in definite proportions, although it is 
difficult to obtain them as such, since the compounds thus formed dissolve 
in all proportions in the melted metals from which they do not differ very 
widely in their melting points. For these reasons it has been questioned 
whether not only amalgams, but any alloy were a true chemical compound. 

Definite compounds have been proved to exist, however, in both 
the native and artificial state. Hiorns gives a good illustration of a 
chemical compound between two metals in the alloy of copper and tin 
which may be represented by the formula SnCu 2 , containing 38.4 parts 
of tin and 61.6 parts of copper. 1 A well-known native chemical compound 
of two metals is represented by silver and mercury, which are found crys- 
tallized together in the following porportions: (Ag 2 Hg, or Ag,Hg 6 ) and 
(Ag 2 Hg 6 ). 

Under the term solution of one metal in another, we understand one 
like ether and alcohol, or any two substances which may be mixed in all 
proportions and will not separate into layers by standing. Solidified 
solution would indicate the solidification of a perfectly homogeneous dif- 
fusion of one body in another and has been represented by glass, which is 
formed in the liquid state at a high temperature and solidifies on cooling 
without separation of the different silicates. Hiorns quotes Mendeleef as 
saying that solutions are fluid, unstable, definite chemical compounds 
in a state of dissociation, and that of such a kind are most metallic alloys. 
They have been considered in the Journal of the Chemical Society as 
solidified solutions of metals which contain definite compounds in excess 
of one of the constituent metals. The subject of solution apparently 
has a most important application in the production of dental amalgams. 

In the same manner that water dissolves saline substances, alcohol 
dissolves resins, ether dissolves fats, etc., mercury dissolves most metals. 
A very interesting phenomenon to observe in this connection is the manner 

1 Hiorns, Mixed Metals or Metallic Alloys. 



264 PLASTICS 

in which most solvents act upon solids (Hiorns). As a rule, the dis- 
solving power of each liquid is confined to a certain class of solids. It 
is also a general rule that the solubility of a body in any medium de- 
pends on a similarity in the constitution of the body and the solvent. 

When a liquid has dissolved all of a solid that it is capable of retaining 
at a given temperature, it is said to have become saturated; but even if 
it be saturated with one solid it may yet take up another, and oftentimes 
the solvent power is thereby increased. 

A general survey of the literature reveals a lack of knowledge of the 
peculiarities of solutions, and appears to explain largely why so much 
importance has been attached to the kind of receptacle to be used for 
mixing alloys with mercury, and the manner of incorporating them. 

It appears important that the subjects of crystallization and diffu- 
sion should be considered in connection with the formation of dental 
amalgams, since they are both closely allied with solutions. The placing 
into solution in mercury of metals or alloys, the subsequent setting 
(crystallization) of the mass, and a final complete diffusion of these 
constituents seems to be controlled by the same agencies as are other 
chemical phenomena. External heat, for example, influences these 
phenomena a great deal, it being considered that a rise in temperature 
of 10° C. will double the velocity of 75 per cent, of all chemical reactions. 

The conversion of chemical energy into heat may also influence these 
phenomena. The condition of contact between the mercury and the 
metal or alloy upon which it is reacting will likewise have its influence 
upon the above phenomena. The internal movements of the compo- 
nent particles of the mass may facilitate diffusion, solution, and chemical 
change. In fact, about the only difference that appears between dental 
amalgams and a majority of chemical compounds is that the metals are 
united by very feeble affinities, and there exists a great tendency for the 
amalgam to possess the properties of its constituents. There are some 
cases where a combination is totally different from either constituent, 
but the general effect is for each constituent metal to maintain its identity. 

The advantage of alloying metals together seems to be to assemble in 
one compound a number of properties which could not be found in any 
one element. Through the work of such men as Flagg and Black, silver, 
tin, copper, zinc, and occasionally gold in small quantities have been 
found to possess more desirable and less undesirable properties than 
any other equal number of metals. Since the work of Dr. Black 1 two 
new but distinct classes of alloy have appeared as the principal products 
of nearly all leading manufacturers. One of them contains from 65 
to 68 per cent, of silver, 26 to 28 per cent, of tin, 3 to 4.5 per cent, of 
copper, and 1 to 2.5 per cent, of zinc. The other contains from 43 to 48 
per cent, of silver, 48 to 58 per cent, of tin, and 1 to 2 per cent, of zinc. 

1 See Dental Cosmos, vols, xxxvii and xxxviii. 



NATURE OF AMALGAM 



265 



The first class is known as high percentage silver alloys, quick setting 
alloys, and Black's alloys, the three names being synonymous. The 
second class is known as low percentage silver alloys, slow setting alloys, 
and plastic alloys. Both classes seem to have grown out of Black's work, 
the latter class undoubtedly with his disapproval. 

Exhibit, Composition, and Physical Properties of Unmodified Silver-tin 

Alloy-. 



Forn- 


i\x. 


How 


Per cent. 


Shrinl 


i- Expan- 




Crushing 


Silver. 


Tin. 


prepared. 


of mercury. 


age. 


sion. 


Flow. 


stress. 


40 


GJ 


Fresh-cut 


45.78 


6 


7 


4U.15 


17b 


40 


GJ 


Annealed 


34.14 


9 


3 


44. GU 


186 


45 


55 


Fresh-cut 


49 . 52 


4 


8 


25.46 


188 


4.3 


55 


Annealed 


32.13 


7-11 


1 


28.57 


222 


50 


50 


Fresh-cut 


51.18 


2 


2-1 


22. 1G 


232 


50 


50 


Annealed 


37.58 


10-17 


0-1 


21.03 


245 


55 


45 


Fresh-cut 


51.62 


0-2 


0-2 


19.66 


245 


55 


45 


Annealed 


40.11 


10-18 





17.53 


27G 


60 


40 


Fresh-cut 


52 . 00 


1-3 





9.06 


239 


60 


40 


Annealed 


39.80 


10-17 





14.10 


297 


65 


35 


Fresh-cut 


52.00 





1-5 


3.67 


290 


65 


35 


Annealed 


33.00 


6-10 





5.00 


335 


70 


30 


Fresh-cut 


55.00 





14-20 


3.45 


316 


70 


30 


Annealed 


40.00 


5-7 





4.67 


375 


72.5 


27.5 


Fresh-cut 


55.00 





2»-42 


3.92 


350 


72.5 


27 . 5 


Annealed 


45.00 


0-3 


0-4 


3.76 


450 


75 


25 


Fresh-cut 


55 . 00 





40-60 


5.64 


258 


75 


25 


Annealed 


50.00 





6-8 


5.40 


3U.J 



Exhibit, Composition, and Physical Properties of M 

Alloys. 



ODIFIF.D MI.YFR-TIN 



Formulae. 
Modifying metal. Silver 
None 
None 
None 
None 
Gold 5 
(J old 5 
Platinum 5 
Platinum 5 
Copper 5 
( topper 5 
Zinc 5 
Zinc 5 
Bismuth 5 
Bismuth 5 
Cadmium 5 
( "admium 5 
Lead 5 
Lead 5 
Aluminum 5 
Aluminum 1 
Aluminum 1 



65 

65 

66 . 75 

66. 75 

61.75 

61.75 

61.75 

61.75 

61 

61 

Gl 

61 

61. 

61. 

61 

61 

61. 

61. 

61 

64. 

64.5 



Tin. 

35 
35 

33.25 
33 . 25 
33 . 25 
33 25 
33 25 
33 25 
33 . 25 
33 . 25 
33.25 
33 . 25 
33 . 25 
33.25 
33.25 
33.25 
33 25 
33 . 25 
33.25 
34.5 
34 . 5 



How 
prepared. 

sh-cut 

Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Annealed 
Fresh-cut 
Fresh-cut 
Annealed 



Per cent. Shrink- 
of mercury, age 
52.33 
33.00 K) 



51 







33 53 7 

47.56 
30.35 '7 
51.87 <) 
37.33 7 
53 . 65 
35.60 5 
56.65 
40.65 
46.26 
23 . 67 G 

57 . 57 

47 . 25 
44.17 
32.76 10 
65 . 00 
46 . 98 

38 . 26 



F.xpan- 
sion. 

1 



4 



1 



9 


23 


68 

9 




KM) 

5 

1 



445 

166 

48 



Flow. 

3 D7 



00 
35 

I Hi 

G2 

07 

68 

8.20 

_ - 
3.50 
1 83 
07 
7s 
58 
40 
54 
88 
18 



12.60 
17.90 



Crushing 

290 

335 

329 

380 

330 

395 

200-273 

250-352 

300-343 

416-450 

200-290 

250-345 

250-288 

308 

225 

290 

290 

276 

198 

213 



The first class seems to be based upon the properties of 72? per cent, 
of silver and 27 \ per cent, of tin, the most important of which is the 
small amount of shrinkage which takes place when this alloy is con- 
verted into amalgam. The second class seems to be based upon the 
dual movement of 50 per cent, of silver and 50 per cent, of tin, which by 



266 PLASTICS 

referring to Dr. Black's charts is seen to be only 2 points. Besides 
the two principal classes of alloys mentioned, there are in the market 
many of the alloys made and used previous to Dr. Black's work. 

Townsend's original alloy of silver 42 per cent, and tin 58 per cent, is 
still used by some. 

Flagg's alloys, especially the one containing silver 60 per cent., tin 35 per 
cent., and copper 5 per cent., are still in the market and used by some. 

There are a dozen or more alloys made to supply the varied demands 
of the profession. Some of them have one or more prominent qualities, 
but, as a rule, they are not free from a reduction in volume at the time 
of and subsequent to insertion, nor do they seem to be based upon any 
particular principle, as are the two classes which have resulted from 
Black's work. Inasmuch as these alloys are also composed of silver, 
tin, copper, zinc, and occasionally gold, they are subject to the same 
consideration as far as physical and chemical properties are concerned. 
It would seem that dental amalgams can best be understood by dividing 
them into the two classes spoken of as high percentage silver alloys and 
low percentage silver alloys. The difference between the two can prob- 
ably be best represented by first considering the most important proper- 
ties of each constituent. 

Silver unites with mercury in definite proportions, and through its com- 
paratively strong affinity for mercury and its large proportions it largely 
controls the setting. It tarnishes quite readily in sulphuretted hydro- 
gen and soluble sulphids. It increases in volume when amalgamated. 
It increases edge strength, lessens the flow, and because of its great 
tendency to crystallize and its property of going into solution in mer- 
cury slowly at ordinary temperatures it causes the alloy to amalgamate 
tardily and the mass to work hard. 

Tin unites with mercury in all proportions at all temperatures, forming 
a weak crystalline compound. It retards the setting, decreases in vol- 
ume when amalgamated, decreases edge strength, increases the flow, 
and imparts plasticity, thus causing the mass to work easily. 

Copper unites with mercury with difficulty at ordinary temperatures, 
although in definite proportions it generally hastens the setting, increases 
edge strength, lessens flow, does not change appreciably in volume when 
amalgamated, and is easily tarnished by sulphuretted hydrogen and 
soluble sulphids. 

Zinc unites with mercury easily and in definite proportions, increases 
in volume when amalgamated, hastens the setting, increases edge 
strength, lessens flow, improves color, and imparts a peculiar smoothness 
to the mass during amalgamation. 

Gold when melted with the other constituents, as most of the present 
alloys are made, adds almost no desirable properties and adds one or 
two undesirable properties. It adds a little to the color and makes a very 
tough amalgam, but it imparts a peculiar pasty springiness which makes 



NATURE OF AMALGAM 267 

it difficult to pack. There are some possibilities in the use of gold in 
small quantities, however, that are not fully developed and which look 
promising. 

From the nature of metallic alloys we may assume that certain pro- 
portions of these constituents enter into combination and other portions 
are simply in a state of mixture or solution. From the similarity of the 
metals we may assume that energetic union has not taken place, and, 
as a result, the portions united chemically are not expected to have 
properties diverging widely from their constituents. 

Since solutions and mixtures generally possess the properties of their 
constituents, we would expect a compound composed of these metals 
to be the sum of the properties of its constituents. Such seems to be the 
case with these alloys. A point to be observed in the consideration of 
these alloys is that one or two metals are used as the base of the alloy 
and the others as modifiers, the attempt being made to add to the prop- 
erties of the basal constituents some of the properties of other constituents. 

A consideration of the alloys now in use. with one or two exceptions, 
shows that the selection of these metals and the proportions of each 
has been made with reference to their physical behavior, special 
emphasis being placed upon decrease in volume, color, and strength. 
Fenchel, 1 however, has for some time been studying amalgams from 
a different point of view. He has taken a break in the cooling curve of any 
liquid (including melted metals) to indicate a change in physical consti- 
tution, and from this traced the crystallizing curve of some of these 
alloys in increasing proportions to each other. He has studied the struc- 
ture of these alloys microscopically as well a-> with reference to alteration 
in form, resistance to stress, specific gravity, and electromotive force of 
currents set up in the mouth by different metals, all of which forms a 
very valuable part of scientific literature. Fenchel 's 2 work may be said to 
follow more closely the chemical phases of alloys than the physical ones, 
while the work of others seems to be devoted largely to the physical 
properties. 

It would appear that a clear understanding of the physical behavior 
of these alloys cannot be had without at least a working knowledge of 
their chemical behavior. For the present however, our knowledge 
of alloys most generally adopted (the two classes mentioned) is con- 
fined largely to their physical behavior. The principal difference be- 
tween the two classes of alloys should be obvious. The first, with more 
silver, less tin, and some copper, is stronger, more stable in form, more 
free from decrease in volume, though it works hard and sets quickly. 
The second, with its high percentage of tin, low percentage of silver, and 
absence of copper is easier to amalgamate, sets slower, and is a little 
lighter in color. These two classes of alloys resemble some of the older 

1 Dental Cosmos, vol. 1, p. 553, and vol. li. p. 1. 

2 For a study of Fenchel's work see his various papers in the Dental Cosmos. 



268 PLASTICS 

as well as many of the newer ones by having some properties in common. 
Contraction and expansion, for example, seem to be phenomena accom- 
panying the setting of dental amalgams. Dr. J. Foster Flagg and the 
previous workers seemed to attribute these properties largely to the com - 
position of the alloy. Dr. Black pointed out that the annealing of the 
cut alloy increased contraction. It has been pointed out that the per- 
centage of mercury used during amalgamation had its influence, although 
it can hardly be regarded as a cause of these phenomena, but rather a 
medium to facilitate further contraction in the already contracting alloys 
and expansion in already expanding alloys. 

The writer has observed that the order of melting the different con- 
stituents, the temperature at which they were kept molten, the time that 
they were kept molten, the temperature at which they were cast, and the 
rapidity of cooling — each could be made to have its influence upon the 
behavior of these alloys. He has also noticed that the size and shape 
of the alloy filing had its influence upon contraction and expansion. 
When we consider that alloys containing 67 per cent, of silver and some 
copper dissolve tardily in mercury at ordinary temperatures, and can 
only be made to form a little true amalgam with the treatment given 
by dentists during amalgamation, it seems entirely within reason that 
the "cut" of an alloy has to do with its condition of contact, and often- 
times presents a typical concrete mass with the undissolved particles of 
alloy, corresponding to the bricks in the wall, and the true amalgam 
formed upon the surfaces of these particles corresponding to the mortar. 

It is not the intention of the writer to convey the idea that the "cut" 
of alloys is an active cause of contraction or expansion, but rather a 
modifier of already existing contraction or expansion, in the same sense 
that an excess of mercury is a modifier of these movements. That the 
composition of alloys has to do directly with contraction and expansion 
seems to be well established. 

With Flagg's work as a basis, Black seems to have established the con- 
traction and expansion ranges for the metals generally used in the 
production of dental amalgams. His results have been questioned, but 
it would seem that it has been done mostly by those using the specific 
gravity method of measuring contraction and expansion which gives the 
actual volume, while Black's measurements were taken with a micrometer, 
which gives linear measurements. (See section on Methods of Measuring 
Change in Volume.) 

Black has assumed that of all the properties which amalgams possess, 
nothing is of as much importance as freedom from contraction. He has 
regarded it as imperative that there must be absolute freedom from con- 
traction and only a minimum of expansion. With this in view, as will 
be observed from his exhibit, he has shown that a minimum of contrac- 
tion, after annealing, took place with 72.5 per cent, silver and 27.5 per 
cent, of tin. Reference to the foregoing pages shows that the alloys made 
after his plans do not contain this amount of silver. They show that 



NATURE OF AMALGAM 269 

certain ranges are adhered to which seem to be from 65 per cent, to 
68 per cent. The reason for not using 72.5 per cent, of silver seems to 
be that a substitution of about 5 per cent, of copper and a little zinc for 
an equal amount of silver would give the same minimum contraction and 
at the same time add some of the desirable qualities of copper and zinc. 

Dental literature fails to show that any definite and fixed amount of 
silver, tin, copper, and zinc can be used and obtain freedom from con- 
traction and expansion. Black states, 1 in describing his experiments 
with the silver-tin alloys, that because metals of a chemically pure 
nature are too expensive for use in dentistry, metals of a less degree of 
purity are used, and as a result no fixed formula is good for general use. 
His exact words are: "From this point another short course of alloys 
only 0.5 per cent, apart was necessary to find the exact balance which 
would produce an alloy that would absolutely lie still while hardening. 
When this was found, it was a good formula for that batch of metals, 
but not for another batch, for the purity might be different, and the 
formula for each new batch of metals had to be found. Therefore, no 
fixed formula could be good for general use. If it were possible to use 
chemically pure metals, a fixed formula would be possible, but such 
metals would be too expensive for use in dentistry." 

The literature from many of the leading supply houses implies that 
their alloys are made after this plan suggested by Dr. Black, although 
some claim that a fixed formula is the basis of their products. A 
review of Fenchel's recent work, and the earlier work of Kirk and 
Burchard, each of whom have viewed more closely the chemical 
phases of alloys, would not suggest the plan offered by Dr. Black. The 
question, " Why does a fixed formula not give a definite movement during 
setting?" has been asked of the writer so many times by teachers and 
practitioners alike that it would seem as though the plan had not been 
understood nor accepted generally by the profession. All seem agreed, 
however, that the plan gives as good results and furnishes us with as good 
alloys as our present knowledge of the subject will permit. It is the 
manner of reaching the result about which there seems to be a differ- 
ence of opinion. The plan implies more than the mere fact that impure 
metals will not give a definite movement. It implies that metals cannot 
be constantly obtained with a definite grade of impurity, for if a metal 
contained a certain impurity in certain quantities every time it was pur- 
chased, allowance could be made for it in the formula. 

While, as a rule, native metals are not to be relied upon, there are 
some instances where the impurity can be determined and allowance be 
made for it comparatively easily. It is quite sweeping in its scope, 
however, to say that refined metals cannot be obtained which are quite 
uniform in their impurities. It is a well-known fact that the character 
of many alloys is altered by the manner of melting and casting. 

1 Operative Dentistry, vol. ii, 310. 



270 PLASTICS 

Oftentimes a certain property of a given combination may be lost 
or obscured by repeated remelting. Most metallurgists are aware of 
the difficulty of maintaining uniformity in an alloy during the melting 
and casting process which is least for two metals and increases when 
three or four are required. Since practically nothing has been written 
by Dr. Black and those adhering to his plan of preparing alloys about 
this most difficult of all metallurgical processes, nor the character of 
these impurities, it would seem probable that too much importance had 
been attached to the presence of impure metals and too little to the 
manner of preparing them. The manner of preparing these alloys, how- 
ever, should be regarded as a modifier rather than as an active cause 
of contraction and expansion. With this in view, it may be said that 
there are five factors which influence contraction and expansion, viz. : 

Composition of alloy (primary cause). 

Manner of melting, casting, and cooling alloy (secondary cause). 

The kind of cut of the alloy (secondary cause). 

The amount of annealing of cut alloy (secondary cause). 

The percentage of mercury used to amalgamate the alloy (secondary 
cause). 

A sixth factor might be said to influence these movements, viz., the 
manner of mixing the alloy and mercury, although it seems to be so nearly 
synonymous with the cut of the alloy that it may be left out of consider- 
ation here. (See Section on Mixing Alloys.) 

Annealing of Alloys. — Dr. J. Foster Flagg seems to have been the 
first to call attention to the fact that alloys which were freshly cut behaved 
differently when amalgamated than the same alloys did after they had 
stood for some time. Dr. Black traced the phenomena through a great 
number of experiments, and finally arrived at the conclusion that the cut 
alloy is hardened by the violence in cutting, the condition thus produced 
being analogous to the condition of the same metals in hammering. His 
earlier observations led to the belief that motion brought about the change, 
but later experiments showed that it had no influence. Oxidation was 
thought to be a factor, but was finally eliminated as one of the causes. 
After a great many experiments it was proved that the change was pro- 
duced by annealing or tempering, i. e. y a molecular alteration of the cut 
alloy. The temperature at which this is produced ranges from room 
temperature upward. If the alloy be subjected to room temperature for 
a year or more, the same effect is produced as when it is subjected to a 
higher temperature for a shorter time. It has been found that the low 
temperature and longer time of exposure bring about a more complete 
annealing. The change can be brought about by subjecting the cut alloy 
to the temperature of boiling water for about twenty minutes, although 
there is not quite the same quality to the alloy that there is when it is 
subjected to a temperature of 120° F. for from two days to a week. The 
amount of heat required to bring about the change is not the same for all 



NATURE OF AMALGAM 271 

alloys, although each formula seems to change in many of its properties 
with this treatment. That this property of these alloys to change by 
so-called "aging" or "annealing" is a physical phenomenon, seems to be 
the opinion of Dr. Black 1 and of Fenchel, 2 but whether it is caused by 
hardening during the cutting process, as suggested by Dr. Black, is a 
question worthy of consideration by those interested in the cause of this 
peculiarity. 

It is well known that the working of metals forces their molecules into 
unnatural positions, and that by annealing they are largely restored to 
their normal state. But it is also well known that the rate and manner 
of cooling of many metals may preserve in some cases and alter in others 
the mode of existence of the molecules at the time they were molten. 
It is also worthy of note in this connection that unequal stresses are 
set up in some castings by cooling the outer layers of the metal much 
quicker than the interior, thereby causing a compression of the interior 
by the outer layers. 

By annealing, which is the reverse of hardening, the metal flows, 
and this tension is relieved. It cannot be stated definitely whether this 
hardness is produced by the casting or by the cutting process, although 
the remedy seems to be well under control. The effect of annealing 
is to remove expansion from those alloys which expand only, and increase 
contraction in those alloys which contract; to reduce the percentage of 
mercury required to amalgamate; to retard the setting; to facilitate 
amalgamation; and in general terms annealing may be said to increase 
both crushing stress and flow. The annealing process effects a reduction 
in expansion, an increase in strength and flow, reduces the percentage 
of mercury required to amalgamate, and facilitates amalgamation simul- 
taneously up to a certain point. (See page 291, Test 6.) 

At this point, which is different for different alloys, no further change 
is produced in contraction and expansion, but all the other changes 
continue with the annealing. The alloy continues to become softer, to 
require less mercury, to amalgamate easier, to flow a little more, and, 
instead of continuing to increase in strength, begins to decrease in strength. 

The annealing process seems to have a zero point for contraction and 
expansion where no further change is produced by annealing, but not so 
with any other property. There is a changing point for crushing stress, 
where the alloy, instead of increasing with annealing, begins to decrease. 
This can be readily understood when it is considered that the anneal- 
ing process is a softening process. Freshly cut alloy sets so rapidly 
because of its denseness and affinity for mercury that thorough amal- 
gamation is impossible. The annealing removes this property of setting 
so rapidly, and gradually admits of a thorough amalgamation; but if 
annealing is carried too far the alloy becomes too soft to admit of the 
production of a filling of maximum strength. No one thing in the use 

1 Operative Dentistry, vol. ii, 309. 2 Dental Cosmos, vol. li, 1909, p. 7. 



272 



PLASTICS 



of alloys seems to be of such vital importance to the profession as an 
understanding of the foregoing phenomena regarding annealing. 

Oftentimes alloys are purchased in quantities with the understanding 
that they have been annealed and that no further change will take place 
as time goes on. No perceptible change will take place in the well-made 
alloys in contraction, but the very best alloys will decrease markedly 
in strength, set much slower, require less mercury, and work very easily, 
within a year's time at room temperature. 

Strength of Alloys. — Strength of alloys usually indicates those prop- 
erties by which alloys sustain the application of force or strain without 
yielding or breaking, and may be considered under two heads, viz., crush- 
ing resistance and flow. Crushing resistance is that property by virtue 
of which these alloys resist force without fracturing, while flow is that 
property by virtue of which they resist force without change in shape. 

Crushing resistance of these alloys may be treated (1) as a property 
of the alloys used to form amalgams, and (2) as a property of the 
amalgam mass. The crushing resistance of these alloys before they are 
combined with mercury is much higher than they are after they are 
cut and amalgamated, mercury increasing the plasticity of all its alloys. 
With this in view, it is obvious that within certain limits any alloy un- 
combined with mercury in the amalgam will increase crusning resistance. 
The crushing resistance of these alloys from which amalgams are made 
is controlled by the composition of the alloy, the amount of annealing, 
and probably (as mentioned before) the manner of casting and cooling. 
Silver adds to this property, copper does likewise, and tin detracts from 
it markedly. Zinc cannot be said to add to crushing resistance, it being 
much better than tin in this respect and a little poorer than silver and 
copper. The crushing resistance of amalgam prepared from these 
alloys presents not only the same phenomena as the alloys, but the addi- 
tional complications arising from the union of the mercury with alloy. 

The following table of results demonstrates that dental amalgams 



have no definite crushing resistance. 1 

Alloy No. 1. Per cent. 

Silver 68.00 

Tin 26.50 

Copper 4.20 

Zinc 1.30 



Alloy No. 2. Per cent 

Silver 65.50 

Tin 25.50 

Copper 6.00 

Zinc 3.00 





Crushing 


resistance. 


Crushing resistance 


?e of amalgam 


Alloy No. 1. 


Alloy No. 2. 


1 day 


435 


pounds 


452 pounds 


2 " 


478 




t 


462 " 


4 " 


485 




u 


453 


24 " 


493 




i 


447 


42 " 


497 




( 


447 


85 " 


475 




( 


433 


205 " 


414 




I 


367 


341 " 


344 




< 


310 


491 " 


187 




' 


163 



1 See a paper by the writer in Dental Review, April, 1907. 



NATURE OF AMALGAM 273 

The two alloys used for these tests were selected from the market not 
simply because they represented some of the best products (all things 
considered), but because they represented about the maximum and 
minimum precentages of zinc to be found in these products at that time. 
The fillings made from these two alloys were allowed to stand, and at 
different intervals six fillings were crushed at a time and an average 
taken as the crushing resistance of the alloy at that time. One thing 
to be observed is the increase in crushing resistance of both alloys up to a 
certain point, after which there was a decrease in crushing resistance 
for a much longer time. 

Another feature of interest is the difference in time required for each 
alloy to reach its maximum crushing resistance. The explanation offered 
for the variation in amount of crushing resistance was briefly this: At 
the time of making the fillings they were composed of undissolved par- 
ticles of alloy surrounded more or less completely with alloy dissolved 
in mercury, forming a kind of cementing substance. From this time 
until the time the maximum crushing resistance was reached the cement- 
ing substance was passing through the process of solidification. 

From the time of reaching the maximum crushing resistance (prob- 
ably from time of amalgamation) there was a gradual breaking down, 
through some of the various ways previously referred to under nature of 
dental amalgam alloys, of the undissolved particles of alloy. As an 
explanation of the difference in time required for the maximum crush- 
ing resistance to be reached, it was stated that it was due to the ease 
with which the alloy amalgamates, and this depends obviously upon the 
composition of the alloy. In this case the alloy containing the least 
silver and the most zinc reached its maximum crushing resistance first. 
From the nature of the metals this should be expected. Since the time of 
these tests other observations have been made which not only confirm 
the ones already mentioned, but appear as indisputable proof that these 
alloys are changing in crushing resistance at the end of three years. 

These tests, according to others started a little later, appear to indicate 
these changes in crushing resistance, although they were not carried on 
long enough to obtain all the change. Later experiments tend to show 
that after the decline in crushing resistance at about the end of one and 
one-half years there is another increase for a year or more. It may be 
said that a cylinder J inch by -J inch of one of the best high percentage 
silver alloys, properly amalgamated, will resist a force of from 450 to 
500 pounds after it has stood a week at room temperature. A cylinder of 
the same dimensions, under the same conditions, of one of the low per- 
centage silver alloys will resist a force of from 150 to 250 pounds. These 
conditions affecting the crushing resistance of dental amalgam alloys 
may be modified by the condition of the cut of the alloy, the manner of 
incorporating the alloy and mercury, the amount of mercury used during 
amalgamation, and the amount of mercury left in the filling. 
18 



274 PLASTICS 

A comprehensive consideration of the actual condition of the amalgam 
mass at and subsequent to insertion reveals that these hitherto regarded 
as primary causes of a modification in the crushing resistance of alloys 
are in reality adjuncts to the real cause. A coarsely cut alloy, for example, 
may be ground in a mortar with sufficient mercury by one operator until 
it is quite fine, while it may be hastily mixed with too little mercury and 
inserted by another. The interior of the two fillings thus made cannot 
be regarded alike either from a chemical or physical standpoint, neither can 
there be anything but a great diversity of changes in crushing resistance 
expected from the two when we consider carefully the thermochemical 
relations of mercury with the constituents of the alloys used to form 
amalgams. The amount of mercury left in the filling influences crushing 
resistance in at least two ways, viz., by its mere presence, and by its 
action with the undissolved particles of alloy. 

If mercury be present in too large quantities, its presence, because of 
its liquid state, lessens crushing resistance markedly. On the other 
hand, if there be too little present, the crushing resistance will be lessened, 
due to incomplete amalgamation. The presence or absence of mercury 
obviously facilitates or retards the breaking down of the undissolved 
particles of alloy. 

Flow of Amalgams.— A solid metal can flow like a viscous fluid if 
sufficient pressure is applied (Hiorns). The property seems to be dif- 
ferent with different metals and varies with different forms of the same 
metal. Some metals with a distinctly granular structure seem to flow less 
than the same metal when in a less granular structure, though the tenacity 
and elongation of the two forms may be nearly identical. The differences 
in the rate of flow between different metals depends largely upon their 
plasticity, by virtue of which they yield to the pressure and allow the mole- 
cules to slip over each other and assume new positions. Dr. Black says i 1 
"If we subject pure silver, say a block 0.1 inch square, to 300 pounds it 
will yield a very little almost as soon as the pressure is applied. Then it 
will yield no more until the weight is increased. If we try a similar block 
of tin in the same way we find it softer. It will yield sharply at 25 pounds, 
and if we leave it under this pressure without increasing it, it will con- 
tinue to yield until it has all crawled out from between the points or been 
reduced to a thin sheet. Therefore, the tin is not only a softer metal, but 
it has a physical property totally different from any possessed by silver, 
the property of continuous flow under a given pressure." This indicates 
the effect of tin and silver upon flow, though it implies that the flow of 
tin is a peculiar property rather than that it is a property of all metals, 
tin being one possessed of a high rate of flow. 

A hard metal like silver has an elastic limit, which must be exceeded 
and the pressure maintained in excess if a continuous flow is produced, 
while a soft metal like tin has practically no elasticity, and is therefore 

1 Operative Dentistry, vol. ii, 317. 



NATURE OF AMALGAM 275 

capable of being changed in form with almost any pressure. The com- 
position of the alloy controls largely the property of flow, the hard and 
elastic metals reducing it and the soft ones increasing it. The effect of 
annealing upon flow depends upon the composition, some formulae being 
affected more by annealing than others. Generally speaking, the soften- 
ing of an alloy by annealing increases flow, although with some formulae 
flow may be slightly decreased by annealing. 

The manner of incorporating the alloy and mercury, percentage of 
mercury used during amalgamation, the condition of the cut, and the 
amount of mercury left in the filling each modify flow, although not with 
regularity even in a given alloy. The least change in composition so 
modifies flow that each of these phases must be considered separately 
with each formula. An excess of mercury left in the filling, however, 
increases flow quite regularly, there being some exceptions in the ternary 
amalgams, which are high in silver and low in tin. The property of flow 
depends largely upon softness and absence of elasticity, and is at its 
maximum in alloys known as low silver alloys. 

Fig. 295 Fig. 296 





Spheroiding of amalgams is a phenomenon associated with flow and 
increase in volume. It has been held that amalgams possessed a strong 
tendency to become spherical in shape, due to the influence of mercury, 
which is spherical in shape when divided finely. This influence which 
mercury is supposed to exert seems to be a misconception of the cause of 
the tendency to spheroid. Mercury is spheroidal or globular in shape 
when divided somewhat, the smaller the particle the more nearly a sphere. 
There seems to have been a tendency to regard this as a property peculiar 
to mercury. This is not true. The property is possessed by other metals 
when in a molten condition. 

The following illustrations show a spheroided filling produced by an 
alloy which increased in volume and flowed easily. It was composed of 
silver, 49 per cent.; tin, 49.1 per cent.; and zinc, 1.9 per cent. Fig. 295 
shows the surface of a filling made from this "plastic" alloy and kept in 
the thermostat at body temperature for eight months. The surface is 
seen to be spheroided. Fig. 296 shows a companion filling like that of 
Fig. 295, except that the walls of the test-tubes are highly polished, this 
being accomplished by making the test-tube with removable bottom, 



276 



PLASTICS 



as seen in Fig. 297. It may be seen that the filling Fig. 296, instead 
of spheroiding, has risen nearly as much at the borders as it has at 
the centre of the filling. The filling Fig. 295 has assumed a much more 
spheroidal surface than the one Fig. 296, due apparently to the walls 
of the cavity being purposely roughened. This spheroidal tendency 
seems to disappear somewhat with alloys high in silver and copper, these 
alloys possessing less flow. It has not been produced to any extent in 
alloys which do not expand decidedly and flow comparatively easily, 
although irregular expansions and contractions appear to produce in 
some instances bulged surfaces and in others concave surfaces in alloys 
possessing little flow and expansion. The consistency of the mass and 
density obtained in working and packing seem to facilitate irregular 
expansions and contractions. Alloys which are in a liquid or semisolid 
condition while being packed will show a tendency to spheroid, not 
because of expansion, but simply because they are not solid. Often- 

Fig. 297 




times the packing of amalgam results in the production of layers which 
have the mercury well pressed out and others which have large excesses 
of mercury, and during the setting process the mercury becomes equally 
distributed, with the result that the more dense layers bulge, while those 
which are less dense become flattened or even concave. 

Thermal and Chemical Relations. — Amalgam, like gold and other 
metals, is a conductor of thermal impressions. Just where amalgam 
stands as a conductor of heat and electricity is not known, although 
it can safely be placed quite near to gold. The composition of the 
amalgam will influence its conductivity. Any rise in temperature 
will usually retard and a fall in temperature will increase conduc- 
tivity, although the resistance of alloys to conductivity does not always 
behave in a manner that would be expected from the nature of their 
constituents. Besides being subject to change in volume during and 
subsequent to their setting, amalgams expand when heated and con- 
tract on cooling. The metals of which these amalgams are composed, 
within certain limits, expand or contract in proportion to the rise or fall 
in temperature, but it cannot be said with certainty that this is true of 
these amalgams. Certain anomalies which are known to exist make it 



NATURE OF AMALGAM 277 

seem possible that certain temperatures with certain formulae might 
result in a variation from the general rule. Dental amalgams are prac- 
tically insoluble in the fluids of the mouth. The common solvent found 
in the oral cavity, lactic acid, affects them but little. There is, however, 
a constant wasting away of many amalgams due to the formation of salts 
which are soluble in the oral fluids. Amalgams that are high in copper 
furnish an example of the constant wasting which may be due to the 
formation of the green basic carbonate in small quantities, or salts from 
the action of hydrogen sulphid and soluble sulphids. The two principal 
classes of alloys now in use are not affected this way to any appreciable 
extent. 

There are probably no alloys in use which exert any particular influ- 
ence upon the tooth tissues except those high in copper. There are one 
or two alloys heralded as great tooth preservers, not simply because they 
are free from contraction, expansion, and flow after insertion, but be- 
cause they possess "antiseptic properties." A critical examination of 
them fails to reveal any reason why they should exert any such influence. 
The action of copper amalgam upon the tooth tissues has been studied 
by Miller, Fletcher, Witzel and others, and the general opinion seems 
to be that it possesses antiseptic properties. 

Use and Manipulation of Amalgam.— The advent of better 
methods and facilities for the construction of inlays and crowns each 
year seems to reduce greatly the amount of amalgam used. It can, 
however, hardly be excluded from any dental practice without at least 
an occasional injustice being done the patient as well as the operator. 

As a general rule, amalgam is inserted in places obscured from view 
and places difficult of access. Among the former may be mentioned 
cavities on the lingual surfaces of all the teeth, distal cavities 



*& 



m 



cuspids, bicuspids, and molars, mesial cavities in the second and third 
molars, buccal cavities in the second and third molars, and cavities on 
the occlusal surfaces of bicuspids and molars. The principal cavities 
which are so difficult of access as to demand amalgam are those 
situated on the disto-buccal and distal surfaces of the second molars 
and all cavities in the third molars. Even these cavities are not 
always difficult to fill with other and better materials than amalgam. 
The preparation of the cavity for the reception of amalgam should be 
done with as much care as for the reception of any other material. 
The teeth should be separated, and any overhanging gum tissue re- 
moved previous to the preparation of the cavity. The rubber dam 
should be adjusted whenever possible, so that disinfection of the cavity 
may be accomplished and the filling inserted in the absence of the oral 
fluids. 

The thing of greatest importance to the dentist is the selection of 
the alloy. Many have doubted the tooth-saving qualities of the high 
percentage silver alloys designed by Black over those of Flagg and the 



278 PLASTICS 

older workers. Many laud the low percentage silver alloys, designed 
not by Black, but by the students of his work, because they are very 
light in color and work easily, while others adhere to copper amalgam. 
In the selection of an alloy from which to make amalgam fillings 
it must be remembered that the qualities most desired are not all incor- 
porated in any one kind of amalgam. Copper amalgam, for example, 
will unquestionably save more teeth than any other kind because it is 
practically free from change in volume and possesses antiseptic prop- 
erties; but it turns so dark in the mouth and causes so much galvanic 
trouble that its use is very questionable. The low percentage silver 
alloys are light in color and work easily because they contain no copper 
and a great deal of tin; but they flow so badly, have so little strength, 
and change so much in volume that their use is also questionable. 
The data obtainable show that the alloys known as high percentage 
silver alloys made by reliable manufacturers possess the greatest num- 
ber of desirable qualities. 

It is very important that an alloy made by a competent maker be 
selected, since there is probably no product in dentistry, and it is 
doubtful if there ever will be, that is subject to more variations and 
is really less understood. There are certain principles which the com- 
petent person will have to guide him, and certain peculiarities about 
these bodies which a few have discovered and mastered. No one 
desiring to serve his patient's best interest will make his own alloy with- 
out some years of study and a generous investment in equipment. He 
may save some teeth, in fact he may save many, but such alloys cannot 
possess uniformly the greatest number of desirable qualities. The high 
percentage silver alloys are made by some manufacturers in two and three 
grades as regards the setting. They are of the same composition, cut 
just the same, and marketed just the same, except that some packages 
may be marked "slow setting," some "rather rapid setting," and others 
"rapid setting." The difference in their production is in the amount 
of annealing given them, annealing causing them to set more slowly, 
and their behavior is usually more marked. 

Alloys marked "rapid setting" will require much more mercury to 
amalgamate them if they have not been in stock long enough to 
become annealed. They will set so rapidly that it is difficult to pack 
them properly, even in cavities of easy access, and almost impossible to 
insert them where there is not ready access. The amount of expansion 
that will take place subsequent to insertion is much greater with im- 
properly annealed alloys. The finished product is represented by alloys 
marked "slow setting." Some manufacturers make their high per- 
centage silver alloys in one grade only. These alloys will have no mark 
to designate their manner of setting. 

The alloy to be selected for general use is the finished product, 
although the occasional use of "rapid setting" alloy when the patient 



NATURE OF AMALGAM 279 

cannot be seen by the operator to finish the filling seems to be desir- 
able. It should be remembered that while alloys marked ''rapid 
setting" expand more than those marked "slow setting," contraction 
and expansion are not controlled by the manipulation of them during 
amalgamation and insertion. The operator may modify these move- 
ments, but he cannot control them, the controlling factor being; com- 
position. 

In choosing an alloy, it should be remembered that the only property 
which can be controlled by the operator is strength, and even then the 
alloy must be properly made or a strong filling cannot be proeluced. 

A strong filling cannot be made from a poor alloy, although a weak 
filling may be made from a good one. The amount of allov necessary 
for the filling should be placed in a small ground glass or Wedgwood 
mortar and ground with the required amount of mercury until the mass 
becomes coherent enough to be turned into the palm of the hand con- 
veniently, after which it should be kneaded rapidly and vigorously for from 
three to five minutes, depending upon the coarseness of the cut, amount of 
annealing, and composition of the alloy. 

A complete union of the alloy and mercury cannot be effected at 
ordinary temperatures. The operator must be guided in amalgamating 
these alloys by the consistency of the mass. It should be fine grained 
and smooth, and tough enough to be rolled out into a lone roll without 
breaking before the mixing is discontinued. 

The amount of mercury to be used with a given weight of alloy is 
slightly more than the weight of the alloy. The proportions given In- 
most makers of high percentage silver alloys are, approximately, 
alloy, 5 parts; mercury, 7 parts, by weight. These proportions are as 
nearly correct as can be determined by experiment, although 7 parts of 
mercurv will be found none too much for alloys marked "rapid setting." 
The low percentage silver alloys of all grades will require less mercury. 
It will seleiom be found necessary to use more than eejual weight of mer- 
cury for a given weight of alloy, to make a smooth, fine-grained mass. 
The amount of mercury to be used with a given amount of alloy of known 
composition is a question which cannot be answereel unless the "con- 
dition of the cut" and the age of the alloy are known. 

The condition of the cut of an alloy will oftentimes affect the rapidity 
with which the alloy becomes annealed in the warehouse or office. 

All alloys require less mercury as they become annealed, hence the 
proportions given by makers of alloys are correct for a comparatively 
freshly made alloy only. 

The older any alloy becomes the easier it works, the weaker it is, and 
the less mercury it requires, although if properly made it will not contract 
appreciably. It may be noted that manufacturers having similar products 
recommend slightly different amounts of mercury to be useel with a 
given amount of alloy. Some products may be marked: "Use 5 parts of 



280 



PLASTICS 



alloy with 7 parts of mercury;" " 4 parts of alloy with 5 parts of mercury;" 
"9 parts of alloy with 11 parts of mercury," etc. Chemical analyses 
show many of these alloys to be nearly identical in composition, but there 
is some difference in the "cut" of them, a little difference in the amount 
of annealing, and probably some difference in the manner of casting and 
cooling, which accounts for the variation of about 10 per cent, in the 
amount of mercury required. The correct amount of mercury to be 
used during amalgamation does not mean the amount of mercury to be 
left in the filling. It means that a slight excess of mercury should always 
be used to start the filling, and as soon as it is noticed it should be re- 
moved. Dr. Black states 1 that "it is certainly best to have just the right 
amount," but in the same sentence states that "superfluous mercury 
does little harm if removed as soon as noticed." 



Fig. 298 





Fletcher's glass mortar and pestle. 

Dr. Black remains practically silent on the subject of "permanency 
of form" or changes in amalgam subsequent to insertion. Consistency 
of the mass seems to be a prominent factor with him. This is unques- 
tionably a vital point in the packing process, but an amalgam which 
packs nicely may be the most unstable kind. 

The factor of supreme importance in the production of a stable amal- 
gam is a fairly complete solution of the alloy in the mercury. This can 
only be produced by the use at all times during the amalgamation pro- 
cess of slightly more mercury than makes a mass. of the consistency to 
pack well. As soon as the mass begins to stiffen and shows a tendency to 
set, any surplus mercury should be removed. There is not even a remote 
possibility of an operator producing a true amalgam out of modern 
high percentage silver alloys under ordinary conditions. The best that 
can be done is to produce as much true amalgam as possible around the 

1 Operative Dentistry, vol. ii, 322. 



NATURE OF AMALGAM 281 

undissolved particles of alloy and yet keep the mass of a consistency to 
pack well. The latter often depends upon the presence of a certain 
number of undissolved alloy particles. 

Alloys low in silver and those high in silver that are very old may dis- 
solve so completely in mercury that the mass is too soft to pack well. A 
perfect filling cannot be made with them. 

The ultimate aim of the operator should be the 'production of a mass of 
amalgam that is both stiff and tough and with the alloy well into solution 
in the mercury. To accomplish this more mercury than is to be left in 
the filling should be used to start amalgamation. This amount is stated 
on the packages of alloy, and is correct for freshly made alloys. Alloys 
one year old or more do not require as much mercury. The alloy and 
mercury may be weighed on a balance or turned out approximately 
correct by an experienced operator from the containers. It is im- 
material whether the exact amount of mercury is weighed or not, as 
the operator never knows whether these proportions are correct. It 
is convenient, however, to have them weighed in the proportions the 
maker has determined for fresh alloys, since a little mercury is easily 
removed during the amalgamation process if it be found necessary. 
Earlier observations of the writer led to the belief that alloy and mercury 
should be determined and weighed carefully, as in that way a mass was 
obtained of a consistency to pack well; but later observations on the 
changes occurring in these bodies subsequent to insertion lead to the 
belief that while the packing of an alloy is a vital point it is not of so 
much importance to the life of the filling as to have the alloy worked 
with sufficient (though not enough to make a sloppy mass) mercury at 
all stages up to the packing. 

After the alloy and mercury have been ground in a mortar, then 
turned into the hand and worked vigorously for a few seconds, it should 
be noted whether the mass is becoming sloppy. If it is, a little mercury 
should be removed quickly between the thumb and forefinger. The 
mass should not be put into pliers, chamois skin, muslin, or anything 
else, as these processes require too much time. Surplus mercury should 
be removed quickly, or the mass stiffens so that the object of the opera- 
tion is partially or wholly defeated. The mass should be quickly turned 
into the hand and again kneaded vigorously. If it again appears a little 
sloppy, remove some mercury as before. Do not remove too much 
mercury, or the alloy will not be anywhere near completely into solution. 
This process should be repeated three or four times, the last time using 
all the pressure that can be exerted in removing the excess mercury, so 
that the mass will be stiff enough to enable it to be packed well. A 
repetition of this process three or four times usually consumes from three 
to five minutes and results in a tough, stiff, and fine-grained mass. 

The question might then be asked, "What is an excess of mercury?" 
And it might be answered in a general way by saving that it is the 



282 



PLASTICS 



i v 



1 




1 25 


35 


10 


30 


15 


35 






30 


10 


35 


15 


7 


7 


7 


7 


7 


7 


fl 12 


12 


12 


12 


12 


12 


1 2 


3 


4 


5 


6 


7 



Black's set of amalgam pluggers. 



difference between the amount used to amalgamate the mass and the 
amount that should be left in the filling. 

Any amount of mercury left in the filling over and above an amount 
which makes a stiff, tough, and fine-grained mass of amalgam would, 

of course, be regarded 
as superfluous. 
Every step in the 
amalgamation pro- 
cess should be done 
rapidly, not allowing 
the amalgam to lie 
still. If the mass lies 
still a few seconds it 
stiffens so much that 
the particles of alloy 
are not broken down 
in the mixing and 
surplus mercury is 
usually retained in 
the mass. The pack- 
ing should be begun immediately, using flat-ended serrated 
instruments. Several instruments have been designed for the 
packing operation, but the consensus of opinion seems to 
favor a flat-ended or cup-shaped serrated instrument such as 
shown in Figs. 299 and 300. 

The round burnisher has been used with some degree of 
success, but it has been proved that it does not give the maxi- 
mum density or adaptation. Pluggers used for foil fillings 
have been used somewhat successfully, but they are too small 
for most places, and as a result chop the amalgam mass to 
pieces and do not compress it. Great care should be exercised 
in packing amalgam, as it is a most difficult material to adapt 
to cavity walls. Too little pressure results in a weak filling. 
Too much pressure, such as that exerted by sudden blows 
from a mallet, disturbs the whole mass, and as a result weakens 
the filling. Heavy, steady pressure gives the strongest and 
best adapted filling. The amalgam mass should not be broken 
up any more than is necessary for convenience in placing it 
into the different parts of the cavity. Much has been said 
in regard to the part of the cavity in which to begin the packing, 
but it is doubtful if any one method can be carried out in all 
cavities. 

In all cases an effort should be made to wedge the amalgam, 
piece after piece, between the opposing walls or between one wall and 
the already condensed amalgam, finishing by wedging some amalgam 



NATURE OF AMALGAM 



283 



between the main mass and the cavity walls. Experience will teach how 
much force can be used in the wedging and what size of pluggers will 
not chop the mass to pieces. Instruments of varying sizes must be in 



Fig. 300 



'% 




'w 




Ivory's set of five amalgam carriers and pluggers. 



284 PLASTICS 

readiness on the table, so that the operator has at his immediate com- 
mand instruments that will compress and wedge amalgam into any 
pocket or crevice that may appear during the operation. Amal- 
gam to be packed properly must be stiff. Soft amalgam cannot 
be packed to make even a fair margin when examined under the 
lens. It is in this part of the work that the modern high percentage silver 
alloys exceed all others, the low percentage silver alloys with no copper 
scarcely deserving comparison. The cavity must have four walls if any 
degree of compression is obtained. With the great variety of matrices 
and matrix retainers provided by the manufacturers, together with the 
facilities at the operator's command for making special matrices, there is 
seldom occasion for inserting an amalgam filling without the cavity 
having four walls. (See Chapter X on Matrices.) 

The cavity should always be filled to overflowing. Amalgam should be 
packed with force, and with as large pluggers as are consistent with the 
operation, upon the orifice of the cavity and left until the mass has become 
hard before any of it is removed. After the mass has hardened some- 
what, surplus amalgam should be removed by carving toward the borders 
with sharp plastic instruments or excavators, so that amalgam once 
packed along the margin and allowed to stiffen will not be disturbed. 
Attention may be directed to the fact that this can only be accomplished 
with the high percentage silver alloys. They excel all others in this 
feature as well as in all features of the packing process. 

Only very light burnishing should be done at the time of insertion 
of an alloy, lest the margins be disturbed. The matrix should be 
removed with great care, or it may disturb the margins or even the bulk 
of the filling. An amalgam filling should be finished in the same manner 
as a gold filling after it has "fully set/' but since this time is indefinite 
(see section on Strength), varying with different alloys, different manipu- 
lation and different ages of the same alloy, no definite time can be 
given for the final finish of the filling. 

If the filling is given its final finish prior to its reaching its maximum 
hardness the best finish cannot be obtained. Generally speaking, forty- 
eight hours is sufficient to elapse between the insertion of amalgam filling 
and the time of giving its final finish, although a week is better. 

Amalgam fillings should be finished repeatedly. Not more than a 
year should elapse after the insertion of an amalgam filling before 
it should again have its margin polished and burnished. 

Attention has been called to the fact that alloys have bulk changes after 
as well as at the time of insertion. This often causes the filling to appear 
spheroided, tilted, warped, or otherwise distorted within a year or two 
after insertion. Such fillings should be ground down with small stones 
and the surface again finished. 

Numerous instruments have been devised for carrying amalgam from 
the table to the cavity, and for finishing the filling after it has stiffened. 



NATURE OF AMALGAM 



285 



Fig. 301 shows an instrument with a spoon at each end which may be 
used w r ith advantage in carrying amalgam in almost all cases. Fig. 302 
shows a somewhat different device, consisting of a tube into which is fitted 



Fig. 301 



Fig. 302 



Fig. 303 




a plunger, both of which are on a regular instrument handle. This 
instrument is useful for carrying amalgam to remote and inaccessible 
cavities, as enough compression can be given to the amalgam by the 



28G PLASTICS 

plunger to make it remain in the cavity, a feat which cannot always be 
accomplished with the spoon instrument. Fig. 303 shows an instrument 
similar in principle, designed by Dr. H. W. Arthur. It is quite as useful as 
the one shown in Fig. 302 in all cases, and much more useful in many cases. 
The sleeve and plunger are constructed on a curve. They are long 
enough to enable the operator to discharge the tube with considerable 
force by means of pressure on the finger piece located on the plunger 
some distance from the end of the instrument. Fig. 300 shows the com- 
bination pluggers and carriers of H. W. Ivory. The ends of the 
instruments used for carrying amalgam are cup-shaped and serrated, 
and the amalgam is carried by being wedged into the serrated cups. 

During the packing operation mercury is often removed from the 
amalgam mass and remains upon the surface. This is almost always 
true if the operator uses a mallet to give sharp blows, but is not very 
marked if the mass has been worked properly and the excess mercury 
removed by good, firm pressure just previous to packing, when the 
regular amalgam pluggers are used. The use of quick blows, as has 
been mentioned before, is bad practice, since it disturbs the amalgam 
mass, even when large pluggers are used, and usually forces too much 
mercury to the surface. As fast as mercury appears at the surface dur- 
ing packing it should be removed hastily with an excavator or other 
instrument and more amalgam inserted into the cavity. 

If there is no easy access to the cavity, pressure enough to bring mer- 
cury to the surface will seldom be exerted. This is also the case if the 
matrix is not used. It is quite generally true that if a little mercury is not 
removed during the packing, the latter has been faulty. Gold foil, silver 
foil, and tin foil have been used to absorb the excess of mercury appearing 
at the surface of amalgam fillings, and little harm has probably resulted, 
although this practice cannot be said to add to the qualities of the amal- 
gam. New alloys are formed upon the surface when any one of these 
materials is used, and experiments have proved that mercury and one 
metal do not form an alloy having the most desirable qualities. 

When tin foil is used to absorb mercury appearing at the surface a 
soft non-crystalline, shrinking alloy results. Similar comment may be 
made upon the use of the other materials, gold being no exception. 

Mercury which has appeared on the surface during the packing, 
providing the packing has been done with care, should be removed and 
not used again without being redistilled. The affinity of such mercury 
for other metals is probably weaker, even though it remains liquid. 

It is possible that the presence of other metals in mercury may be found 
to improve its different qualities, but it has not yet been done. On the 
other hand, mercury which has been removed from amalgam during 
packing has almost invariably been found 1 to contain more tin than 

1 The author. 



COPPER AMALGAM 287 

other constituents. Dr. Black's later observations seem to confirm this, 1 
but in the same chapter he states that "if the alloying is a perfect com- 
bination I have reason to believe that no one metal will be dissolved 
more than another." It is a fact, however, that when two metals are 
cooled, certain alloys of these metals may solidify first and a more fusible 
alloy of these metals is left, and is known as the eutectic alloy of these 
metals. It is a general rule that this defect is intensified when four or 
five metals are used, as is the case in the production of dental amalgam 
alloys. With these facts in view we may assume that an ingot of alloy 
before it is cut contains quantities of globules or strata of eutectics which 
may be more soluble as well as more fusible. Mercury which has had 
ever so slight a contact with alloy should be discarded, since it will pick 
up some of the alloy and have its affinity partially satisfied. 

General Considerations. — Washing Amalgams. — Much importance 
has been attached to the washing of amalgam just prior to its insertion 
or during the mixing process. Such substances as sodium carbonate, 
dilute acids, ether, chloroform, and alcohol have been used, but with 
doubtful value. The only advantage in washing amalgam is to remove 
some of the metallic salts which form upon the surfaces of the particles 
of cut alloy. It has been stated that washing increases shrinkage 
(Flagg), but this can easily be accounted for when it is considered that 
alloys free from shrinkage have been made only since Black's work. 
Washing amalgam with such substances as chloroform and alcohol will 
loosen the metallic salts sufficiently to permit the mercury to act more 
energetically. As a result, the filling will be at the time of insertion a 
little lighter in color, usually a little stronger, and the mass will set 
somewhat faster. Washing usually consumes enough time to allow the 
mass to stiffen somewhat, and in this case it is a decided injury to the 
filling. The material used for washing generally remains to a consider- 
able extent as foreign matter in the filling. This in no case improves 
the integrity of the filling, and in some cases works marked injury. 

Empirical Methods of Mixing Alloy and Mercury. — Since the intro- 
duction of amalgam as a filling material, many have attributed their 
success with amalgam to some particular method of incorporating the 
alloy and mercury. Some have used the mortar alone, others the hand 
alone, and still others, various rubber receptacles. Many dentists seem 
to have lost sight of the fact that they are attempting to amalgamate a 
hard alloy. As soon as a little alloy is dissolved the mass stiffens some- 
what, and if the amalgamation is not carried to completion quickly, large 
particles of alloy remain undissolved. This is particularly true when the 
hand alone or a rubber finger cot is used. Alloy must be broken down 
quickly if it is to be done as completely as possible. It has been sug- 
gested that perspiration from the hands injures the amalgam. This is 

1 Operative Dentistry, vol. ii, 318. 



288 PLASTICS 

true only to the extent in which it remains as foreign matter in the filling, 
and with ordinary precautions this injury is imperceptible. A small 
mortar (see Fig. 298), preferably Wedgwood, for starting the amalga- 
mation and the hand for its completion, seems to be the only equipment 
used by those who are studying the subject carefully. 

Copper Amalgam. — Copper amalgam differs so markedly from all 
other amalgams, both in composition and behavior, that it deserves 
separate consideration. The foregoing data apply only in slight degree 
to copper amalgam. It is an alloy of copper and mercury, and may be 
made by adding freshly precipitated and washed metallic copper to an 
excess of mercury until the solution is complete; the excess mercury is 
then removed by compressing the mass in chamois skin. The portion 
which does not pass through the chamois skin is packed into moulds and 
allowed to stiffen. The product can be purchased in the form of small 
tablets, which may be softened by heating gently in a spoon (Fig. 304), 
after which it may be moulded and packed into the cavity. Many den- 
tists have made copper amalgam by grinding copper filings in a mortar 
with dilute acids and washing with a variety of substances immediately 

Fig. 304 




Heating spoon for copper amalgam. 

before insertion of the amalgam. A far better method, and one which 
yields a product of greater purity and uniformity, has been suggested 
by Dr. E. C. Kirk. It is done by precipitating the copper directly into 
the mercury by electrolysis. "This may be done conveniently," says 
Dr. Kirk, " by pouring a quantity of mercury into a suitable glass vessel 
— a small battery jar, for example — and suspending a thick plate of 
copper, by means of a wooden support, some distance above the surface 
of the mercury. 

"A saturated solution of cupric sulphate is then poured into the jar until 
the copper plate is completely submerged. The cathode pole of a battery 
or other source of electrical current is then connected with the layer of 
mercury, and the anode with the copper plate. All of the cathode elec- 
trode that Is in contact with the cupric sulphate solution should be 
insulated with gutta-percha, and only the point which is in contact with 
the mercury left exposed. The passage of the current causes solution 
of the copper from the anode and deposits it in the mercury contin- 
uously as long as the foregoing conditions are maintained. The pre- 
cipitation should be continued until the mercury is saturated, which 



BUYING AND KEEPING ALLOYS 289 

will be evidenced by the appearance of the characteristic red color of 
the excess of copper at the cathode pole. 

" When the saturation point has been fully reached the mass should be 
washed, first in dilute hydrochloric acid and then in water, dried and 
compressed, as is usual with this amalgam when prepared by the ordi- 
nary process." Copper amalgam prepared in this way does not change 
in volume as a result of the union of mercury with the copper, either in 
the mixing or subsequent to its insertion into the oral. cavity. The only 
alteration in form that occurs is the comparatively small one resulting 
from the thermal changes. It is antiseptic. These two qualities make 
one of the best tooth preservers now in use, although it has other 
qualities so undesirable as to exclude its use in a great majority of 
cases. It turns almost black in most mouths, has a peculiar metallic 
taste, is sometimes a marked cause of voltaic disturbance, and if mois- 
ture through any cause enters between it and the walls of the tooth the 
latter becomes discolored. Often, although no visible leakage of the 
rilling is apparent, there is discolored tooth tissue, due probably to the 
absorption of the salts of copper into the dentinal tubules. Copper 
amalgam is not quite as indestructible in the fluids of the mouth as other 
amalgams, as it readily forms salts which are either dissolved or carried 
away by abrasion. This is commonly shown by a sort of cupping out 
of the surface of the filling. 

Classification of Amalgams. — Amalgams may be divided into classes 
according to the number of constituent metals. A binary dental 
amalgam may be represented by copper and mercury or palladium and 
mercury, each of which has a very limited usefulness in dentistry. Some 
of the older alloys of silver, tin, and mercury, such as that designed by 
Dr. Townsend, represent what may be called a ternary dental amalgam. 
Amalgams of silver, tin, copper, and mercury, such as designed by Dr. 
Flagg, may be said to be quaternary dental amalgams. This class is 
also represented by the so-called plastic amalgams made since 1895-1896, 
and composed of silver, tin, zinc, and mercury. The high percentage 
silver amalgams, composed of silver, tin, copper, zinc, and mercury, 
may well represent a quinary amalgam. The terms binary, ternary, etc., 
have not gained in popularity with the profession in the last decade, 
although amalgams are in use representing each of the classes mentioned. 

Buying and Keeping Alloys. — The question, " Which is the best alloy 
to buy?" is asked so often that it seems quite certain that the pro- 
fession in this particular does not exercise the same judgment with 
which it selects other dental materials. It indicates quite clearly that 
there is yet much mystery surrounding the purchase of an alloy. When 
supplies the nature of which is not understood are required, the 
majority of the profession select them from a dealer who is believed to 
be reliable in this respect and who is known to be wholly reliable in 
others. As a rule, the larger supply houses are best equipped for 
19 



290 PLASTICS 

distributing uniform supplies of all kinds, and most likely to secure the 
services of competent men to manufacture their products. This is true 
in the manufacture of alloys, and should be used as a guide in their 
selection. Sometimes a good product comes from a dealer who is not 
well or favorably known, but this is the exception rather than the rule. 
Alloys and cements above all other products should be made and placed 
upon the market by competent chemists if the dentist is to be rewarded 
for his energies. The practising dentist should never attempt the manu- 
facture of these products himself without first spending considerable 
time preparing himself by learning the peculiarities of these products 
with special apparatus built for the purpose. 

Dentists, as a rule, are kept changing alloys by solicitous dealers 
who advance this or that quality of their alloy as a cure-all. For 
example, one dealer lauds his product as being superior because it 
contains more silver than a like article made by another. Another 
makes the same claims regarding the quantity of zinc in his product. 
Others advance the argument that the manner of cut of their manu- 
facture has much to do with the success attending its use, and so it is 
with nearly every dealer. These arguments generally reward the dealer 
with sales because dentists, as a rule, are not sufficiently informed on the 
subject to enable them to judge the merits of the products themselves. 

It is true that some of the best manufacturers differ as to what con- 
stitutes the "best alloy all things considered," but, as a rule, the 
difference of opinion is an honest one rather than an effort on the part 
of the producer to lessen the first cost of the article. This is shown by 
several leading dealers' products, which are found to contain from 65 
per cent, of silver to 68 per cent, of silver, jet each will claim to have 
an alloy made after Dr. Black's plans, etc. The maker who uses 68 per 
cent, of silver knows that he obtains a little stronger filling, although 
he is conscious of the fact that it works a little harder and sets faster 
than one that contains only 65 per cent, of silver. On the other hand, he 
who uses 65 per cent, of silver knows that his product works a little 
easier and sets a little slower, although he is conscious that it is a little 
weaker. The maker who uses only 65 per cent, of silver probably con- 
siders it better to give the operator a little more time to work than to 
have a little stronger filling. 

The same is true of the quantity of zinc now used in high percentage 
silver alloys. Some claim better and permanent light color in the 
mouth as a result of the use of a little more zinc, while others admit a 
loss in color as a result of its elimination, but claim to have a product 
more permanent in form. Neither disputes the other's claims, but each 
places greater stress upon the distinctive qualities of his product in 
contrast to those of his competitors. Thus it becomes a matter of 
judgment which quality is of most importance. 

The leading dealers' high percentage silver alloys are all good, well- 



BUYING AND KEEPING ALLOYS 291 

made, uniform products, and except for the differences mentioned, they 
are nearly of equal value from a practical standpoint. Whether an 
alloy contains 65 or 68 per cent, of silver is not a guide to the quality 
of either. The same is generally true with the small quantities of zinc 
now used, although it is quite generally understood that zinc, while it 
improves color, facilitates change in volume subsequent to insertion 
when used in any quantity. Dentists cannot rely upon the quantity of 
each or any constituent as a guide to quality, although present knowl- 
edge of the subject confines the qualities of each constituent for the 
best alloys to the ranges stated on page 265. All things considered, 
the high percentage silver alloys are best, and should be chosen by 
dentists. 

There are perhaps some places where the quick-setting properties 
make the use of these alloys questionable, but taken as a general rule, 
dentists soon learn to open up the orifice of the cavities and master the 
manipulation of these quick-setting, stiff-working products. When pur- 
chasing an alloy from a manufacturer who makes his product in both 
filings and shavings, the filings should be chosen. Shavings, as a rule, 
are not of the proper shape to permit their being dissolved readily in 
mercury. Not all manufacturers make their products "cut in two 
forms." As some dentists demand them, the maker sometimes can 
hold his trade by no other means than by supplying shavings to those 
who want them. 

Some makers of high percentage silver alloys make only one grade of 
alloys as regards setting qualities, while others make their product in 
two or three grades. This, too, is usually done to catch trade, since most 
makers are aware that if more than one grade is supplied, some of the 
grades are imperfect products at the time of making. "Rapid setting," 
"slower setting," and "slow setting" are terms used to designate these 
products. They are the same in composition, but have not had the 
same amount of annealing. The accompanying chart shows the action 
of one of these alloys in the hands of the writer. 

Formula— Ag 68, Sn 26.50, Cu 4.20, Zn 1.30 = 100. 



Test 


Time of 


annealing 


Percentage of 


Point.- of 




lumber. 


at 49° C. 


mercury. 


expansion. 


Manner of setting. 


1 







63 . 00 


19 


Extremely rapid 


2 


1 


day 


59.00 


7 


Slower 


3 


2 


days 


58.00 


3* 


u 


4 


3 


" 


57.40 


n 


<( 


5 


5 


(t 


57 . 25 


4 


" 


6 


7 


" 


57.00 


\ 


u 


7 


10 


a 


56.60 


\ 


a 


8 


15 


u 


56.10 


\ 


<< 


9 


20 


" 


55.50 


\ 


it 


10 


25 


" 


54 . SO 


\ 


" 



Tests Nos.' 4 and 5 indicate about the manner of setting that most 
completed products would possess and would be marked by the maker as 



292 PLASTICS 

"slow setting." Tests Xos. 2 and 3 indicate approximately the man- 
ner of setting that the products of some makers would possess and 
would be marked " rapid setting," "slower setting," etc. These products 
are but partially annealed, and may be regarded as incomplete. If the 
product of a manufacturer who makes several grades is to be used, the 
one marked "slow setting" should be chosen for immediate use. If the 
alloy is purchased in quantities, it is often advisable to select the "slow 
setting" for immediate use and some of the other grades for future use, 
because the "rapid-setting" alloys become "slow setting" by standing 
at ordinary temperatures. 

Unfortunately, the date of manufacture of alloys is not stamped upon 
the package. This should be done, as the dentist has no protection 
against the purchase of old alloys which are unfit for use, other than 
the seller's honesty. As a rule, alloys which have stood in the market 
six months have deteriorated somewhat, and in a year they are not 
good for general use. Dentists should select their alloys with this in 
view. Buying in large quantities is not always safe, even if care has 
been exercised in selecting the product. Alloys should not be kept near 
a heater, in the sun during the summer months, or in an overheated 
room for any length of time. Alloy for immediate use must be at hand, 
but the remainder should be kept in a cool, dry place. Otherwise even 
a comparatively small stock of alloy will become so much annealed in a 
short time that it should not be used. 

Discoloration of the Tooth Tissue. — This seems to occur much more 
rapidly with some amalgams than with others. It has been observed 
that the high percentage silver alloys and the so-called plastic alloys 
make amalgams which do not perceptibly discolor the tooth tissues if they 
are properly manipulated. Both of these classes of alloys remain quite 
light in color in almost all mouths, although the "plastic amalgams" are 
the lighter of the two. From this it would seem that the composition of 
the alloy from which the amalgam was made controlled the amount of 
discoloration which took place on an amalgam filling. Dr. Black and 
Dr. Adolph Witzel attribute the lack of discoloration of tooth tissue by 
some amalgams to the fact that the filling was imperfectly adapted or had 
decreased in volume, thus allowing moisture to penetrate between the 
walls of the tooth and filling. This is probably an important factor in 
this connection, but the composition of the alloy seems a greater one. 
Examination by the writer of a large number of mouths containing 
fillings made of alloys composed of approximately 49 per cent, of silver, 
49 per cent, of tin, and 2 per cent, of zinc failed to reveal any evidence 
of discolored tooth tissue, and only very few fillings that were even 
darkened. A similar examination of a large number of fillings made 
from alloys composed of approximately 68 per cent, of silver, 26.5 per 
cent, of tin, 4.2 per cent of copper, and 1.3 percent, of zinc that showed 
a majority was discolored somewhat, but no evidence of discolored 



DISCOLORATION OF THE TOOTH TISSUE 293 

tooth tissue was found. Of course, an examination of this kind does 
not reveal the condition of the surface of the filling next to the tooth, 
except at the margins. It does, however, show the tendency of these 
alloys to discolor when exposed to the action of the saliva. Both of these 
alloys, it will be noted, contained zinc, and the lighter of the two con- 
tained no copper. Products similar to Flagg's GO per cent, silver, 35 per 
cent, tin, and 5 per cent, copper alloy have been known to discolor 
quite markedly in most mouths, and have been the cause of much 
discolored tooth tissue. Since no such combination known is free from 
shrinkage, it is impossible to say whether such discolored tooth tissue was 
caused by the shrinkage or the character of the amalgam, or both. It is 
probable that amalgams similar to that of Dr. Flagg's, which do not 
contain zinc, will cause discolored tooth tissue if used at a stage where 
shrinkage is taking place or if they are imperfectly adapted. 

Much has been claimed for the presence of zinc in even small quan- 
tities in alloys used for dental amalgams. Just how the profession will 
consider it in the future cannot be definitely stated, since most of the 
writings on the subject agree that it is the constituent which facilitates 
change in volume subsequent to insertion. The same writers agree, 
however, that it prevents discoloration of the amalgam as well as of the 
adjacent tooth tissue. 

Elimination of zinc from high percentage alloys would leave a product 
composed of silver, tin, and copper, the same as Dr. Flagg's, although 
the percentages would be slightly changed. Dr. Black states 1 that "0.5 
per cent, of zinc is inadmissible for the reason that the amalgam will 
continue to change bulk very slowly for five years or longer." If his 
latest judgment in this respect were to be carried out by the makers 
of these products, there would not be much difference in color between 
alloys made after his plans and those of Dr. Flagg, although they would 
probably have the advantage of being free from shrinkage. 

It is probable that the makers of amalgams w r ill endeavor to incor- 
porate the zinc in such a manner as to keep the amalgams from moving 
after insertion, rather than permit a reduction in color and a step back- 
ward. Plans have already been advanced by one or two makers of 
alloys whereby the zinc is incorporated into the amalgam almost inde- 
pendently of the other constituents. Dr. Black states that this action of 
zinc in the change in bulk was so subtle that it w r as not at first dis- 
covered, and suggests its elimination from these products. It is doubt- 
ful whether the profession will agree to return to amalgams of a darker 
color, even if there is some change in bulk. With the promise of new 
methods of incorporating zinc and other products it is questionable 
whether this will be necessary. 

Alloys which have not been cut too coarse, and have been worked 

1 Operative Dentistry, vol. ii, 312. 



294 



PLASTICS 



thoroughly by the dentist to a relatively complete solution of the alloy in 
the mercury, have long given enough service to warrant their continued 
use. The dentist can prevent much of the change in bulk by his selec- 
tion of alloy and manipulation of it. 

Some claim that amalgams may discolor the dentin by a percolation 
into the dentinal tubules of salts formed when amalgam was placed 
in contact with the open ends of these tubules, the filling remaining 
water tight. The writer has had his attention called to this by two or 
three practitioners who are using copper amalgam in an occasional 
remote cavity. Amalgam which has discolored usually takes on a 



Fig S05 




Black's micrometer. 



blackish hue. Tooth tissue, on the other hand, may appear brown, black, 
or green, the latter being the case when a silver-tin alloy containing a 
large percentage of copper is used. The extent of the discoloration of 
tooth tissue depends, apart from the composition of the alloy, largely 
upon the access of the saliva to the surface of the filling next to the cavity 
walls and upon the size of the dentinal tubules. If the tubules are 
quite small or are obliterated, there will not be an extensive discoloration. 
If the amalgam is one which discolors readily and there is opportunity for 
the saliva to penetrate between the cavity wall and the filling, rapid and 
extensive discoloration will occur if the dentin is capable of being pene- 



MEASURING CONTRACTION AND EXPANSION 



295 



trated. On the other hand, if there is very little access for the saliva 
the discoloration will be slow and less extensive. 



Fig. 306 




A A represent two jewelled bearings from which swing the two levers D D. These two levers 
are counterbalanced by the two adjustable counterweights B B, which enable one to bring the 
instrument into contact with the filling at E with a minimum amount of pressure upon the 
ailing. As these levers are small steel needles, this amount is very small when the counter- 
weights are adjusted, and at the same time allows one to use very long levers, which is a 
decided advantage. C represents a small mirror in front of which swings the longer lever D, 
which must coincide with the fine line across the mirror every time a reading is taken at the 
vertical bar F. This vertical bar is ground to a knife-edge, so that it easily falls upon or 
between the graduations on the disk G. The bar also contains graduations which are the same 
distance apart as the threads on the micrometer screw H, thus enabling one to tell at a glance 
how many turns the screw has mad3. 

Measuring Contraction and Expansion. — Doubt has been expressed in 
regard to the accuracy of a micrometer for determining contraction and 



296 



PLASTICS 



expansion. Those who have had experience in determining densities by 
the specific gravity method are usually skeptical about the accuracy of 
the tests for the alloys if the maker has used a micrometer. The 
micrometer, however, has gained in popularity since alloys have been 
made which have practically only one movement, viz., expansion. The 
Wedelstaedt steel test-tube, as modified by the writer, shown in Fig. 297 
has gained in popularity simultaneously with the micrometer as a 
receptacle for making test fillings. These receptacles are used in con- 
nection with micrometers of various designs. Fig. 305 shows the one 
designed by Dr. Black, Figs. 306 and 307 show the one designed by the 
writer. A casual observation will show that these instruments measure 
the upward flow of metal caused by an amalgam which expands, but this 
is not the case when the amalgam contracts, as contraction tends to 
take place in the manner shown in Fig. 308. The micrometer, a much 
more convenient means of determining expansion than the specific 
gravity method, is usually employed for this purpose, although it is con- 
sidered of little value in determining contraction. While the specific 







Fig. 


308 












— — — T 


f 








« 


1 

1 

1 

1 

1 








1 
1 

\ 
\ 


1 

1 








1 
1 



Diagram of amalgam shrinkage. 



gravity method is considered the most accurate means of determining 
both contraction and expansion, its results do not always coincide with 
those taken on a micrometer for expansion. An amalgam which shows 
an expansion on the micrometer may show a contraction when tested by 
the specific gravity method. This is usually the case when alloys are 
coarsely cut and are not well broken down in the mercury during 
amalgamation. Such an amalgam filling which is smooth at the time of 
making becomes somewhat porous within a few hours, owing to the 
absorption of mercury from the interstices on the surface to the interior 
of the filling. The specific gravity method will measure these inter- 
stices and show a contraction, while the micrometer giving only a linear 
measurement may show that the linear dimensions have actually 
increased. 



CEMENTS 

The cements obtainable for dental purposes consist chiefly of the 
zinc oxychlorids and three classes of oxyphosphates. The oxysulphate 
has been used some in the past, but hardly deserves consideration any 



CEMENTS 297 

longer. The oxychlorid is formed by the combination of highly cal- 
cined oxid of zinc and zinc chlorid. The oxyphosphates are formed by 
the combination of a more or less modified phosphoric acid with one or 
more oxids of metals. 

Zinc chlorid + . Oxid of zinc = Oxychlorids. 

Oxid of zinc = Basic zinc phosphates] v on a _iiif'i; 



Phosphoric acid 



( Non-alkaline. 
Oxid of copper = Oxyphosphate of copper. 

(Beryllium. 
Silicia = Silicate cements. 
Aluminum. 
Calcium. 



The foregoing diagram of the different cements shows at a glance 
the classification of the substances which form these compounds. For 
example, the first compound is composed of zinc chlorid and an oxid 
of a metal. 

The three classes of oxyphosphates are composed of oxids of metals 
with phosphoric acid. The zinc oxychlorids have been used for a 
variety of purposes, but have been almost displaced by newer com- 
pounds known as improved oxyphosphates. When calcined zinc oxid 
is combined with zinc chlorid, a very white basic zinc salt is formed 
which sets quite promptly, although its physical properties which meet 
the requirements of dentistry are few in number. 

Recent improvements in the three classes of oxyphosphates have 
placed them where they meet many of the long sought for qualities of 
this material. These compounds resemble amalgams in that the powder 
portion is usually in excess in the mass after it has set. Dr. Ames has 
"somewhat figuratively" applied the term "basic" to these compounds, 
although it is hardly in keeping with chemical nomenclature. 

When calcined zinc oxid is brought into contact with phosphoric 
acid a part of the oxid goes into solution, but as a putty-like consistency 
is approached, the mass consists of many times one equivalent of the 
base for each one of the acid. The oxyphosphates (also the oxychlorids) 
assume the aspect of concrete at the time of setting by containing a 
cementing medium of zinc phosphate holding together zinc oxid 
granules. 

The first class of oxyphosphates, known as the basic zinc phosphates, 
has been divided into two classes according to the modifiers in solution 
in the phosphoric acid, one known as alkaline and the other as non- 
alkaline. The liquid portion of the alkaline cements differs from that 
of the non-alkaline in the quantity of sodium phosphate it contains. 
When metaphosphoric acid is combined with sodium phosphate the 
former takes on a smooth, glassy consistency, and is known as glacial 
phosphoric acid, although, as suggested by Dr. Ames, it is in reality 
orthophosphoric acid and orthophosphate of sodium, as a result of 
effecting the combination in the presence of water. The addition of 
this sodium salt aids very materially in handling and working the acid, 



298 PLASTICS 

but it makes a soft, porous cementing medium. Other metals than 
the alkaline group have been added to the phosphoric acid, prin- 
cipally in the form of phosphates, to form an improved product much 
less porous than the alkaline cement. Not all of the sodium has been 
discarded as some analyses show. Some of the good qualities of the 
sodium have been retained apparently, by substituting such metals as 
magnesium, aluminum, silver, zinc, and copper for a portion of the 
sodium. The powder portion of the basic zinc phosphates contains 
other materials than zinc oxid, some of which are added for the pur- 
pose of pigmenting and some for the improvement of the integrity of the 
cementing medium. Oftentimes these materials found as modifiers in 
the powder portion are partially or wholly insoluble in the liquid portion. 
In this case, other things being equal, the cement mass would resist 
attrition somewhat better. 

The presence of partially or wholly insoluble substances in the powder 
portion of these cements cannot, however, be taken as a guide to the 
property of resistance to attrition. Like sodium phosphate, they can 
hardly be dispensed with entirely, except in cements used for crown-, 
bridge- and inlay-work, and then their elimination is questionable. Of 
such substances the oxids of aluminum and silicon are notable. 

Substances which are known to hasten or retard the setting proper- 
ties of these cements are added in small quantities to the powder as well 
as to the liquid portions. Among such materials are calcium oxid and 
sodium phosphate, the former hastening and the latter retarding the 
setting property. The properties may be modified widely by the treat- 
ment given the different oxids, especially zinc oxid. Zinc oxid may be 
prepared by heating zinc hydroxid, the loss of water converting it into 
the oxid. The same compound may be prepared by igniting metallic 
zinc in air. Zinc oxid which has been heated comparatively little will 
make a soft powder and a sticky cement, while if the zinc oxid is cal- 
cined a great deal it is flint-like and makes a less sticky cement. This 
is taken into consideration in the production of the basic zinc cements, 
some products appearing to contain two or three grades, as regards the 
amount of calcining. 

The second class of oxyphosphates, known as oxyphosphates of 
copper, are similar in construction to the basic zinc phosphates, and 
what has been said of modifiers in the powder and liquid portions of 
the basic zinc compounds applies equally to this class. Generally 
speaking, they differ from the basic zinc compounds by having oxid of 
copper for the base of the powder instead of oxid of zinc. 

The third class of oxyphosphates, known as silicate cements, differ 
from the basic zinc compounds, by being composed of oxids of other 
metals than zinc, with phosphoric acid. Among such metals may be 
mentioned beryllium, calcium, aluminum, and silicon. Since even less 
work has been done with this class of cements than with the other 



CEMENTS 299 

classes it is uncertain what the liquid or powder portion will eventually 
be. It is claimed that a certain well-known product has aluminum 
phosphate in large quantities and zinc phosphate in small quantities in 
its phosphoric acid. H. Carlton Smith stated in a paper before the 
American Academy of Dental Science at Boston, February 7, 1906, that 
he believed these claims were faithfully carried out. During the last 
year the writer has examined several of these products, and found the 
one referred to by Dr. Smith very constant in composition and to con- 
tain the ingredients claimed by its promotors. 

Some other silicate cements have appeared to differ somewhat from 
the one mentioned, both in the liquid and the powder portions, the 
greatest difference being in the quantity of beryllium. While in general 
terms the base of nearly all cement liquids is phosphoric acid, and 
the base or foundation of the powder portion is an oxid of a metal, it is 
no assurance that the compounds are not very complex bodies involving 
intricate chemistry. The virtue of almost any of these compounds is so 
dependent upon some particular modifiers of oxid of zinc and phos- 
phoric acid that the use of other liquids and powder than those intended 
by the manufacturer means certain disappointment to the user. For this 
reason it is never safe to substitute for either the liquid or powder of a 
given make the liquid or powder of another make. This is also true 
with different classes of oxyphosphates from the same maker. 

A given phosphoric acid of a given concentration will combine with 
certain of these metallic oxids and produce a compound of a certain 
insolubility, possessed of certain working qualities and capable of a 
minimum of change in volume. If phosphoric acids of other concen- 
trations or phosphoric acid containing the phosphates of other metals 
be substituted a change of properties very detrimental to the product 
is likely to occur. 

Attention may again be directed to the fact that phosphoric acid for 
certain of these cements contains non-alkaline metallic phosphates 
almost to the point of saturation; this is necessary in order to bring 
about the desired qualities of the cement. Certain of the newer 
products are compounded in this way. In addition, some of the slow- 
setting cement liquids contain the alkaline phosphate of sodium, which 
partially neutralizes this tri-basic acid, assuming that orthophosphoric 
acid is used. Such a phosphoric acid is loaded to the fullest extent with 
modifiers, and is apt to crystallize on standing. To avoid this crystalli- 
zation, Dr. Ames conceived the idea of furnishing his cements com- 
pounded for quick setting and furnishes extra some of the acid prepared 
with phosphates, to retard the setting and add a little to the adhesive 
properties, etc. This he calls "flux." 

Some interesting phenomena usually occur in the "loading" of phos- 
phoric acid and in neutralizing it with sodium salts. Orthophosphoric 
acid is theoretically a tri-basic acid, and forms mono-basic, di-basic, and 



300 PLASTICS 

tri-basic salts, the first two being acid to litmus and the latter alkaline 
with sodium. It may be seen, however, with the aid of litmus, that 
sodium carbonate of varying dilutions will bring about the transition 
from acid to alkali so gradually that no definite quantity can be said to 
neutralize an aqueous solution of phosphoric acid. The following 
equation indicates the amount of sodium carbonate that would be ex- 
pected to neutralize phosphoric acid: H 3 P0 4 + 3NaOH = Na 3 P0 4 + 
3H 2 0; experiment, however, shows that approximately one-half the 
quantity indicated by the formula is all that is necessary to bring about 
an alkaline test with litmus. 

Another phenomenon accompanies the use of varying dilutions of 
sodium carbonate. After a given quantity of sodium carbonate has been 
ascertained which will neutralize phosphoric acid it is found necessary to 
alter this, with changes in temperature and changes in dilution of the 
sodium salt. These phenomena appear to be due to the difference in 
dissociation of the three hydrogens of phos- 
Fig. 309 phoric acid. Ostwald has stated that not only 

does the dissociation H 3 P0 4 = H + H 2 P0 4 occur 
comparatively easily, but in measurable amount. 
The further dissociation H 2 P0 4 = H + HP0 4 he 
states takes place only in a very slight degree, 
and the third dissociation, HP0 4 = H + P0 4 , 
is exceedingly slight. This seems to account 
for these phenomena reasonably well when 
phosphoric acid and sodium carbonate are 
used, but when phosphoric acid is loaded to, 
or nearly to, saturation with one or more modi- 
fiers, and the setting qualities of a cement made 
from it seem to demand the introduction of 
alkaline phosphate, certain phenomena appear 
which are less easily explained. It would seem that the liquid portion 
of cements thus compounded would rarely ever withstand the vicissi- 
tudes to which they are subjected. 

It is found that if certain precautions are observed, most cement 
liquids stand for a time without crystallization. Any portion of the 
cement liquid that is subjected to the changes in humidity of most 
rooms that occurs with the change from natural to artificial heat will 
have a strong tendency to crystallize. When crystallization has once 
begun, it tends to spread to any uncrystallized portion and upon newly 
made liquid of the same composition. When the ordinary bottle, 
either with rubber or glass stopper, is used, there is, even with care, the 
chance of leaving some of the liquid exposed to the air around the neck 
of the bottle. This may be avoided somewhat by transferring the liquid 
from the container, as it is purchased, to the telescoping cap bottle 
(Fig. 309). This requires less care to prevent some of the liquid 




CEMENTS 301 

remaining around the neck exposed to the air. A further precaution is 
to be observed when removing the liquid from the bottle. Only a 
-perfectly clean glass dropper should be used. A non-corrodible spatula 
may safely be used if it has not previously been employed to remove 
powder from the bottle, and is free from any other foreign substance 
which by combination with the acid would interfere with the equilibrium 
of composition in the liquid. 

Several modifications may be made in the setting qualities and strength 
of a cement by the physical condition of the powder portion. A given 
coarse powder mixed with a phosphoric acid solution may be slow setting ; 
the same powder when reduced to a finer state may be rapid setting 
because of the increased surface of the zinc oxid presented for action to 
the phosphoric acid solution. An analogous process occurs in most plas- 
tics, except some of the alloys, which would also act this way were it not 
for the annealing which takes place more rapidly with the finer cut alloy. 
Some cements which are supposed to be alike will act differently, on 
account of this difference in the fineness or coarseness of the powder 
portion. This is, obviously, analogous to other plastics. Each com- 
bination has only a given coarseness and fineness which will yield given 
physical characteristics. The strength of cements may be modified by 
the size of the granules of their powder portion. In some cements 
the adhesive property seems to have been developed to the slight detri- 
ment of strength, such cements being intended for setting inlays, etc. 
The powder portion of these inlay cements is often much finer than the 
powder of the same cement used for fillings. There appears to be a 
limit, however, to the fineness of powders, strength falling off if they are 
extremely fine. Strength likewise decreases if the powder is very coarse. 

Another modification of these cements may result from an exposure 
of the powder portion to the atmosphere of the room. The oxids will 
hydrate and absorb carbon dioxid and become hydrated carbonates of 
the metals of which they are composed. 

It is doubtful whether the products of the best manufacturers contain 
impurities which appreciably modify the behavior of these cements. 
Until recently, however, impurities have not been watched for with as 
much care, and both liquid and powder have been subject to them. 
Much of the irritation to the pulp from cements has been attributed to 
the presence of arsenic as an impurity. Chemical investigation has 
proved that while arsenic is invariably present as an impurity in oxid 
of zinc it is in the form of insoluble zinc arsenite and inert to the pulp 
tissue. Impurities have been found in the liquid of the cheaper cements, 
but the liquids of the better products contain little or nothing that was 
not intentionally placed there by the manufacturer. 

A commerical glacial phosphoric acid has a somewhat variable com- 
position. It is the metaphosphoric acid containing some sodium phos- 
phate, and because of its hygroscopic properties a varying amount of 



302 PLASTICS 

water, which slowly converts the metaphosphoric acid to orthophos- 
phoric acid. The liquids of the better cements, however, are not com- 
merical products. They contain, very often, a number of ingredients 
in small quantities, but the effect of each ingredient upon the integrity 
of the cement mass, its solubility, its volumetric change during setting, 
and rapidity of setting, is known. A bottle of carefully prepared cement 
liquid may, after standing for some time, appear somewhat turbid 
toward the bottom of the bottle and appeared contaminated with im- 
purities in some or all of the constituents. This is often observed when 
a portion of the bottle of liquid has been used. Such phenomena are 
usually due to the formation of layers of different densities, and the 
residue of a bottle of liquid almost always has a higher specific gravity 
than the liquid formerly had. Such liquids do not indicate the presence 
of impurities as much as the attempt on the part of the maker to com- 
bine the properties of a number of substances, the result being a liquid 
which will not withstand the vicissitudes to which it is subjected. 

Properties and Uses of Cements. — The better products are tested 
for volumetric change at and subsequent to insertion, in the same 
manner and with the same instruments as alloys. The Wedelstaedt 
steel test-tube is used as a matrix to retain the cement, and a micrometer 
such as shown in Fig. 306 will permit subjecting the filling to a water 
bath at any stage during the setting by placing the micrometer in a 
small container at the time of taking the first reading and allowing 
water to flow into the container at the desired time. 

It is very esential that cements be tested both dry and wet; with 
alloys no action with the water will modify change in volume or 
strength. Not so with the cements. A cement which will shrink 
markedly when dry may expand very much if subjected to a water 
bath during the earlier stages of the setting. Like alloys, the best 
cements expand slightly. The expansion of the cements at and subse- 
quent to insertion may be modified by at least two factors, viz., the stiff- 
ness of the mix and the time that moisture is allowed access to the cement. 

If moisture is kept from a cement intended to be hydraulic there 
may be no expansion, while if it is subjected to moisture early in the set- 
ting it may expand several points. With a stiff mix, as used for fillings, 
less expansion is likely than when less powder is incorporated and the 
consistency appears about midway between that of a cement mixed for 
cementing inlays, bands, etc., and that mixed for a filling. The creamy 
mix, as a rule, gives the greatest expansion, although there must not be 
too little powder, as is often the case when mixing for inlays, etc., or 
there will be a slight shrinkage. The strength of the cements is modi- 
fied to even a greater degree by the manner of mixing than is the 
strength of alloys. Almost any strength may be obtained from 300 
pounds to 1500 pounds on a cylinder J inch high and \ inch in diam- 
eter. As in the case of alloys there is no definite time during which 



■1 



CEMENTS 303 

cements will resist a given force. Some of the present cements, how- 
ever, appear to change less in strength than most alloys do if they are 
kept from the oral media. The union between many of the oxids and 
modified phosphoric acid solutions is effected much more energetically, 
and in consequence is less likely to result in the menstruum acting 
upon the solid under ordinary conditions. It is nearly impossible, 
however, to obtain a perfect chemical product from the cements under 
the manipulation given them by dentists. 

Attention has already been called to the excess of zinc oxid granules 
which is always present when cement is mixed for a filling. When it 
is mixed for cementing bands, inlays, etc., this is not always true. 
When cements are subjected to the oral media the integrity of the 
cement mass usually suffers, especially in the case of the basic zinc 
phosphates and oxyphosphate of copper, both of which are subject to 
the solvent action of basic and acid products of the mouth. The presence 
of lactic acid in the mouth due to the process of fermentation and its 
action upon the basic zinc phosphates and oxyphosphates of copper 
are well known. Ammonia water also dissolves some of the oxids, 
notably zinc oxid, and as it is doubtful if a basic zinc phosphate is ever 
composed of the exact combining weights to form a basic phosphate, it 
is not unreasonable to suppose that some of the basic phosphate 
cements will disintegrate as a result of thii action. Ammonia infre- 
quently occurs as such in the mouth, but the ammonium salt in the 
form of chlorid does, and its action upon the basic oxyphosphates much 
resembles that of ammonia, although it is slower. 

Much is claimed for the insolubility of the newer products known 
as silicate cements, but their origin is so recent and, with one or two 
exceptions, they are so changeable in composition that few data of a 
practical nature are obtainable. Laboratory tests, however, are en- 
couraging, but before being accepted they must be verified by practical 
tests. Dr. Joseph Head 1 has pointed out that any test which might be 
applied in the laboratory is only a guide to the solubility of cements in 
different mouths. He has shown that a 1 to 500 lactic acid and water 
solution will turn tooth enamel white in one-half hour, while a 1 to 500 
lactic acid and saliva may not attack it appreciably for weeks, and yet 
the latter solution may turn blue litmus brilliantly red and possess an 
acid taste. This phenomenon he attributes to the restraining power of 
saliva upon lactic as well as other acids. He also points out that this 
property of the saliva varies in different individuals and in the same 
individuals at different intervals. 

Dr. Kirk 2 has pointed out that mucin is probably the protective 
element in the saliva which prevents the action of highly dilute acids 
upon the teeth. He has also called attention to a quite analogous 

1 Dental Cosmos, August, 1908. - Ibid., vol. lii, p. 735. 



304 



PLASTICS 



phenomenon, 1 in which he shows that both acid and basic sodium 
phosphate may exist in the same saliva and not be neutralized by each 
other. Thus, it seems that the solubility of the cements depends more 
upon the condition of the saliva than the mere presence of any solvent 
coming from the saliva, products of fermentation, or the food. 

The uses to which the basic zinc phosphates may be put are about as 
variable as are the cases requiring the services of the dentist. The 
popularity of the inlay method of filling teeth has increased its use- 
fulness in retaining fillings. The increased amount of orthodontia 
done from year to year has demanded more of this material for the 
retention of bands, etc. Its use as a filling, however, is probably as 
limited as ever, it being regarded as a temporary filling in every sense. 
Many specimens have been exhibited in which these cements have 
served as a filling for several years, but such cases are the exception 
rather, than the rule. These cements are valuable in temporary opera- 
tions on the teeth of adults and children. They are indispensable in 
retaining fixed bridge-work and crowns and are invaluable in elimi- 
nating undercuts and forming the base of cavities for all kinds of fillings. 



Fig. 310 




The oxyphosphate of copper cements may be used like the basic zinc 
phosphates, although they are more applicable to the teeth of children 
and of such adults as require the salutary effect of the copper salts. 
These cements are much more bland than either the basic zinc phos- 
phates or the silicate cements. When placed near a pulp or the peri- 
dental tissues these copper salts seem to exert a beneficial rather than a 
destructive influence, as also in the pulp chambers and canals of decidu- 
ous teeth. The silicate cements have not been in use long enough to 
enable the profession to judge of their properties although they seem to 
make very good fillings. They are almost devoid of adhesiveness, which 
excludes them from use for retaining bands, inlays, crowns, bridges, etc. 
They are much more translucent, and much less soluble than any other 
cement used in dentistry. 

1 Dental Cosmos, April, 1907. 



_t~ 



CEMENTS 



305 



Mixing of Cement. — To mix the powder and liquid properly they 
should be placed upon a large glass slab which is attached to the cabinet 



Fig. 311 



or a thick one which can be easily grasped with the hand and held 
still during the mixing (Fig. 310). The powder and liquid should be 
20 



306 



PLASTICS 



placed some distance apart, so that a small amount of powder can be 
cut into the amount of liquid thought to be necessary for the operation, 
with a large iridio-platinum or good grade German silver spatula, if the 



Fig. 312 





Ash's agate-ended plastic instruments for inserting, packing, and polishing silicate cement. 



CEMENTS 307 

cement be a basic zinc phosphate or oxyphosphate of copper. If the 
cement be a silicate cement and the operation require the translucency 
obtainable with these bodies, a bone or agate spatula should be used, but in 
no case should a steel spatula be employed. Iridioplatinum is probably 
the best material for a spatula in operations where a slight modification 
of color is not objectionable, although it is doubtful if there is sufficient 
abrasion from this kind of spatula appreciably to modify the color of 
the silicate cements. The objection to most agate and bone spatulas is 
their shape, which will not enable the operator to form a thorough mix 
in the time at his disposal before the cement begins to set. The most 
practical spatula for the basic zinc phosphates and oxyphosphates of 
copper seems to be one of good German silver. It is not attacked ener- 
getically by the phosphoric acid solution and is not abraded sufficiently 
to be injurious to an appreciable extent to these cements. The reverse 
is true when a steel spatula is used, as phosphate of iron usually is 
detrimental. 

Each addition of powder should be cut into the liquid in a clean man- 
ner and mixed until a thorough incorporation of the two is in evidence 
before another addition is made. This should be continued until the 
desired consistency is obtained. For retaining inlays, bands, crowns, 
etc., the mixture must be of a consistency to flow quite freely. For 
fillings the mass should be of a putty-like consistency, which can be 
packed. The demands of the dentist are so varied that the consistency 
of the mass before it is set determines the amount of powder to be 
added to a given amount of liquid. No definite proportions can be 
given which will meet the requirements of all cases. The silicate cements 
and oxyphosphates of copper employed principally for fillings permit of 
more definite proportions than the basic zinc phosphates which are 
used for a variety of purposes. There is one exception to mixing 
cements to a putty-like consistency for fillings, viz., in the use of the 
oxyphosphates of copper. These cements appear to develop a greater 
density and to disintegrate less easily when mixed to a creamy con- 
sistency, although in this condition they are not always as easily in- 
serted into a cavity. It is often necessarv to vary the consistencv with 
the temperature of the room and that of the mixing slab. Since heat 
facilitates chemical change, it is often necessary to make the mix a little 
thinner in hot weather or if the slab is quite warm. 

All instruments used in mixing cements should be scrupulously clean. 
Foreign substances which would not injure an alloy, might work marked 
injury to a cement. The presence of moisture before the cement has 
been placed may work an injury to the quality of the cement formed, 
but with the newer products it is often desirable to allow moisture to 
have access to the fillings after it has been placed. This applies 
obviously only to the cements compounded for this purpose and desig- 
nated as hydraulic cements. 



308 PLASTICS 

Nearly all basic zinc phosphates and oxyphosphates of copper in use 
at present are compounded so as to act properly when subjected to 
moisture almost immediately after being placed. A few of the older 
products, however, must be protected from moisture for hours after 
being placed. This may be done by covering them with wax or 
paraffin. The silicate cements are very susceptible to moisture. A 
mere trace seems to injure them markedly, even after they have been 
placed several minutes. These cements should be inserted in the entire 
absence of moisture and covered for several hours with some protective 
material. Waxes and paraffins are the principal substances adopted 
for this purpose. 

The writer has had the greatest success with the sticky wax made after 
the formula of Dr. Fred. A. Peeso, consisting of pure white wax, 16 parts; 
white resin (colophony), powdered, 3 parts; gum dammar, powdered, 
3 parts. It is light in color and extremely adhesive, the latter quality 
being of the greatest importance in protecting the filling from moisture. 

What has been said of packing alloys is also true of the cements, 
with the exception of the oxyphosphates of copper, some of which are 
best mixed to a creamy consistency and often most readily inserted 
without a matrix. The basic zinc phosphates and silicate cements are 
best inserted with a matrix if the cavity be a proximal or proximo- 
occlusal one. All cavities which are not four walled should be converted 
into such by the use of the matrix. 

The same matrices used for alloys may be used with the basic zinc 
phosphates, the majority being thin steel. Unlike the steel spatula, the 
steel matrix does little or no harm because there is little abrasion, and, 
besides, the acidity of the liquid has been lessened by the basic powder 
portion. German silver and copper may also be used for matrices with 
the basic zinc phosphates and oxyphosphates of copper, but not always 
with the silicate cements. They should usually be inserted with a cellu- 
loid matrix. If there is slight or no abrasion between the silicate cement 
and metal matrix, little or no harm results; but if some abrasion occurs, 
discoloration and injury to the integrity of the cement are apt to take 
place. The basic zinc phosphates and oxyphosphates of copper may be 
packed and trimmed with the same instruments as those used for alloys, 
although it is better not to use instruments with serrations. 

Fig. 311 shows very desirable forms of instruments for use in hand- 
ling these cements. One or two of the ball-shaped instruments should 
be ground so that only one-half of the ball is left, to make them flat 
instead of round packing instruments. An amalgam plugger or two 
may have the serrations ground off, leaving them flat and smooth so 
that the cement will not adhere so tightly to the packing surface of the 
instrument. The silicate cements may be packed and trimmed with steel 
instruments if care is exercised not to rub the instrument over the cement. 
The makers of these products generally condemn the use of steel instru- 



GUTTA-PERCHA 



309 



ments, because in unskilled hands the result is a discolored filling. 
Agate, bone, or tortoise-shell instruments (Figs. 312 and 313) are invari- 
ably advocated, although according to the general judgment they are 
not delicate enough to permit the technique necessary for good results. 
If the packing is done with as little rubbing as possible, steel instru- 
ments may be used with little danger of discoloration. 

The same is true in trimming. The instruments should be sharp 
enough to avoid unnecessary friction. The agate and bone instruments 
advocated by their makers are practical for large cavities where the 
margins extend well from the proximate surfaces of the teeth, and for 
occlusal, buccal, and lingual cavities. 

The cements may be finished with paper or cloth strips or disks as 
soon as they have hardened, varying with different cements, the manner 
of mixing, and the presence or absence of water. 



Fig. 313 




Tortoise-shell points to be mounted on any instrument handle. 



Care should be exercised in the selection of strips or disks for use 
on the silicate cements. If the abrasive material on the strip or disk be 
dark colored there is liable to be a surface discoloration, due to the 
incorporation of the abrasive material into the surface of the filling. 

Steel burnishers used to finish metal fillings should not be used to 
finish any cement filling after the cement has hardened sufficiently to 
abrade them while rubbing them over the filling. More importance is 
attached to the finish given the silicate cements than upon the basic 
zinc phosphates or oxyphosphates of copper. Owing to the solubility 
of the two latter classes a finish will last but a short time. 

It is claimed by some that a polished surface on the better silicate 
cements will last longer and aid materially in preventing an alteration 
of the pigments in them. This, however, is a recent observation, and 
has not been verified by a sufficient number to warrant the acceptance 
of this theory. Undoubtedly a polished surface will more closely approxi- 
mate the luster of the enamel and make a more finished piece of work, 
but if the stability of the pigments is dependent upon a polished surface, 
even to a slight degree, there are certain to be discolored fillings. 



310 PLASTICS 



GUTTA-PERCHA 

The gutta-percha of commerce is the concrete juice of the Isonandra 
gutta, an evergreen tree of the order of Sapotacese, found chiefly in the 
Malay peninsula and archipelago. The juice is secured by tapping 
the cambium layer of the tree and catching the juice as it exudes. 
The juice thus obtained undergoes many processes for purification 
before it is formed into sheets as seen in commerce (see works on Gutta- 
percha), and several more before it appears in the market for dental 
purposes. 

"The purified gutta-percha probably consists of a hydrocarbon 
(pure gutta) having the formula Ci Hi 6 ; albane, C 4 oH 6 40 3 ; and a variable 
compound named guttane. Pure gutta possesses all the good qualities 
of gutta-percha in a much enhanced degree, becoming soft and plastic 
on heating and hard and tenacious on cooling without being in the least 
brittle. The resins seem to be simply accessory components which have 
a decidedly detrimental effect when they preponderate. Water, wood 
fibers, bark, sand, etc., occur as mechanical impurities of gutta-percha." 
(Obach.) 

It will be seen that gutta-percha resembles rubber in composition, 
since it consists chiefly of a hydrocarbid, in which the two elements, 
carbon and hydrogen, are present in similar proportions. Gutta-percha 
resembles rubber also in its origin, both coming from the milky juice 
of certain trees, although some claim a superior quality of gutta is 
obtained by processes of extraction from the dried leaves and buds. 
Apart from these similarities, the two substances are not so very 
similar. Rubber is a very elastic body, i. e., it is capable of returning 
to its original form when a mechanical force causes it to undergo a 
change. Gutta-percha, on the other hand, has a tendency to preserve 
the change in form produced on it by the action of similar forces. 
Rubber containing no sulphur softens under heat, as does gutta-percha, 
but preserves its elasticity if the heat be kept within certain limits; 
beyond a definite degree of heat its physical and chemical properties 
are altered. Gutta-percha, on the contrary, under heat which does 
not exceed 110° C, is very plastic and malleable and preserves on 
cooling the appearance and shapes which have been given to it while 
in the plastic state. Several other differences between the two exist, 
such as the action of light, moisture, and air, the action of sulphur on 
the two, their non-conducting properties, etc., though the principal 
difference in this connection is the one in their elasticity. 

Because gutta-percha preserved the shape given to it exceedingly 
well for a material of its nature, it was introduced as a filling material 
into dental practice, according to Dr. Kirk, about the year 1847. Since 
that time several secret preparations have been introduced, all of which 



GUTTA-PERCHA 311 

have probably been gutta-percha to which other substances have been 
added for the purpose of changing the physical properties by improv- 
ing the desirable ones and masking or destroying the undesirable ones. 
One of the first to appear was by Dr. Hill, which received his name. 
Several analyses of Hill's stopping have been given, all of which are 
probably untrustworthy. Dr. Herman Prinz, 1 however, gives the for- 
mula of Hill's stopping as: Feldspar, 1 part; quartz, 1 part; quicklime, 2 
parts; gutta-percha base-plate, a sufficient quantity to make a stiff mass. 

Dr. Prinz does not give his authority for this formula, although it 
would seem that if both feldspar and quartz were added it would be 
done empirically. Dr. Kirk has said : " It subserved so useful a purpose 
that it received the tribute of wide imitation; in fact, the white gutta- 
percha preparations of the present day had their foundation in this 
imitation." Undoubtedly the present gutta-perchas and their modifi- 
cations have gradually developed from this preparation, in the same 
manner that other filling materials have become very complex com- 
pounds as a result of years of study. The gutta-perchas for dental use 
are divided into three classes according to the temperature of softening: 
"Low heat," softening below 200° F.; "Medium heat," becoming plastic 
at 200° to 212° F.; "High heat," 210° to 220° F. The three kinds are 
often numbered to distinguish them from each other, one manufacturer 
assigning Xo. 6J to the low heat, No. 1\ to the medium heat, and 
Xo. 8^ to the high heat gutta-percha. According to Kirk the low 
heat gutta-percha contains about 1 part by weight of gutta-percha to 
4 of zinc oxid ; in medium heat the ratio is 1 to or 7 ; and in the high 
heat specimens the gutta-percha is almost saturated with zinc oxid. 

In some of the products materials other than zinc oxid are used to 
mix with the gutta-percha. The proportions, however, remain about 
the same. Calcium carbonate, some of the sulphates, silica, and other 
oxids are among the substances claimed to be substituted for the zinc 
oxid. 

Physical Properties. — Gutta-percha in the pure state is almost color- 
less, the small amount of coloration varying from rose to grayish 
white. It is inodorous and insipid. It is naturally cellular in 
structure, but if drawn out its texture becomes fibrous and more 
resistant lengthwise and less transversely. It will not break until a 
load of about 25 kilograms per square millimeter has been applied to 
it. It is but slightly elastic. It is a very good non-conductor of both 
heat and electricity. It contracts in hardening, i. e., cooling. Its 
density varies from slightly under that of water to slightly over it, 
depending upon the compression given to it in forming it into 
sheets. To the vital tissues it is very bland. Gutta-percha which 
has been in the mouth for some time often becomes harder, and 

1 Dental Formulary, p. 21. 



312 PLASTICS 

its surface porosity is increased. Kirk states in regard to these 
changes: "The increased hardness is observed in such situations as 
those in which putrefactive decomposition occurs; that is, in places 
where there is an evolution of hydrogen sulphid; the gutta-percha ap- 
parently undergoes a species of vulcanization. It becomes somewhat 
porous in those situations where the formation of a solvent is active 
(lactic acid), which abstracts the soluble zinc oxid from the mass. 
The pink variety containing the insoluble mercury sulphid does not 
become porous, but wears with a comparatively smooth surface 
when subjected to attrition." This would seem to explain some of 
the changes very satisfactorily, but there are some where other 
explanations would seem to apply. For example, gutta-percha which 
has been exposed to air and light becomes friable like rosin, and 
its solubility in certain reagents is increased. If, however, the 
gutta-percha be submerged in water no perceptible change is pro- 
duced. Oxygen aided by light is supposed to be the factor of prime 
importance in this change and as a result the process is generally 
spoken of as oxidation, although some refer to it as resiniflcation, since 
the extent of the change depends largely upon the resin present in the 
gutta-percha. Thus, it would seem that oxygen produces a condition 
in gutta-percha quite analogous to the one observed by Kirk which 
he has attributed to the action of sulphids. In both cases, however, 
whether the gutta-percha be in the mouth or out of it, the change is 
apparently what he has called "a species of vulcanization." What 
Kirk states regarding the porosity of the surface is probably true. It 
would seem, however, since the solubility of gutta-percha in alka- 
lies increases with oxidation, that there was a chance for the surface 
to become porous in the absence of lactic acid. Gutta-percha in the 
normal condition is insoluble in dilute acids and concentrated alkaline 
solutions. It is soluble in carbon bisulphid, chloroform, coal-tar oils, 
benzol, boiling ether, and oil of turpentine. 

Indications for Employment. — Gutta-percha in its white and pink 
forms, and in the three classes, low, medium, and high heat, is used 
as a temporary filling material for both the temporary and perma- 
nent teeth. Its non-conductivity makes it a good material to place 
near the pulp. Conditions are met in which the use of gold, amalgam, 
basic zinc phosphates, and silicate cements alone is contraindicated 
because of the close proximity to the pulp. In such cases a thin layer 
of gutta-percha may be placed over the pulp, after which the permanent 
filling materials may be inserted without serious injury to the pulp 
from thermal changes. It has been quite a common practice to fill 
deep undercuts with gutta-percha and cover it with amalgam or cement, 
or cement and gold, but recent requirements for better cavity forma- 
tion seem to have created a demand for a harder material, and as a 
result the basic zinc phosphates have been more widely used. 



GUTTA-PERCHA 313 

Gutta-percha is generally used to fill the pulp chambers of devital- 
ized teeth, but even here it is, as a rule, conceded better practice to 
confine it to the root portion of the pulp cavity, and to fill any 
remaining portions which require a similar plastic material with one 
of the best basic zinc phosphates. It has been used extensively for 
cervical cavities in molars and bicuspids which do not extend to 
the masticating surfaces, but the demand for better oral hygiene is 
such that this practice has become less common except for relatively 
temporary operations. It has been used for all classes of cavities in 
the temporary teeth, and seems often to be practically the only avail- 
able material which will meet the requirements of these cases. There 
is a tendency, however, to use less gutta-percha in the temporary 
teeth because of the demands of orthodontists for the retention 
of normal contact when restoring proximate portions of these teeth. 
There is likewise a tendency to use it less in other locations in the 
deciduous teeth for the reasons previously given in regard to better 
oral hygiene. 

To the casual observer it might seem from this that there was little 
use to which gutta-percha might be put. Such, however, is not the case. 
Instead, there are a great many places where gutta-percha seems to 
satisfy more of the requirements than any other material. There are 
places, however, where its insertion represents almost anything but 
cleanliness. Many have a misconception regarding the impermeability 
of gutta-percha, and as a result are reluctant to substitute other 
materials when it can as well be done. 

Dr. Black 1 says: "The trial that has been made of gutta-percha for 
the exclusion of moisture for long periods of time from ocean cables 
has shown its absolute impermeability." The fact that gutta-percha, 
used as a cover for ocean cables, is almost impervious, is true, but it 
is to be regretted that this statement was not qualified somewhat, 
because as it stands the average person would take it that gutta-percha 
was likewise impervious in the mouth. 

Attention has already been called to the fact that gutta-percha did 
not combine perceptibly with the oxygen of water, but that it did 
with the oxygen of the air in the presence of light. Under the latter 
conditions gutta-percha undergoes rapid decay, and gives off an acrid 
odor. Kirk has called attention to the action of sulphids upon gutta- 
percha. Thus, while gutta-percha is impervious when inserted, it 
undergoes decay from at least two causes. Of course it will remain 
in the mouth for a considerable length of time before the decay be- 
comes very perceptible, but fillings of long standing will show consid- 
erable change. 

Gutta-percha is still a very useful material, but it should not be 

1 Operative Dentistr}-, vol. ii, p. 362. 



314 PLASTICS 

allowed to remain exposed to the oral fluids for any great length of 
time. It may be used to set almost all kinds of crowns on roots 
which have been prepared for their reception, but should be allowed 
to remain for a comparatively short time only. Often an operation 
may be nearly complete, but the operator may wish to do something 
more before a crown is placed permanently. In such cases a little 
gutta-percha which has been made plastic by heat may serve to retain 
a crown. 

The same is true regarding its use for fillings. In an extensive inlay 
practice gutta-percha is almost indispensable as a temporary stop- 
ping from the time the cavity is prepared until the inlay is ready to 
be set. It is usually best not to allow much time to elapse between 
the preparation of the cavity and the setting of the inlay, but in an 
extensive practice occasions continually arise in which this is necessary. 
Gutta-percha may be used for sealing in treatments in the teeth when 
the cavity is sufficiently large to permit of its adaptation without 
compression of the pulp, or where the stress of mastication will not 
dislodge it. Dr. Black 1 states that " It should be the only material 
used for sealing in dressings and for the temporary stoppings in con- 
nection with treatments/' As he says, gutta-percha is a trying material 
to handle until the technique of its manipulation has been mastered, 
but it is difficult to understand why he should declare that it is the 
only material which should be used for sealing in dressings, etc., when 
it is generally conceded that the basic zinc phosphates fulfil many 
requirements better than gutta-percha. For example, suppose an acci- 
dental exposure is made in the preparation of a cavity of a young 
patient where the pulp is near the surface, or suppose that the ex- 
posure has been made by caries and the pulp is in a highly inflamed 
condition. In either case the medicinal agent would probably be 
mixed with one of the nicely prepared oxids as a carrying agent and 
gently placed over the exposure. 

As a sealing for the cavity, shallow as most are, nothing would 
seem to meet the requirements as well as one of the adhesive basic 
zinc phosphates, which could be applied without perceptible pressure. 
There are many cavities which present a different problem. They may 
be deep and easy of access. In such cases gutta-percha would be 
preferable to any other material. 

One of the first considerations is that the surfaces to which gutta- 
percha is applied should be dry and free from greasy materials. This 
may be accomplished by the adjustment of the rubber dam or by the 
use of rolls and the aid of an assistant, according to the case treated. 
If the gutta-percha is to be inserted into a cavity the walls should 
be parallel or even have slight retaining points, although in most cases 

1 Operative Dentistry, vol. ii, p. 361. 



GUTTA-PERCHA 
Fig. 314 



315 




Thermoscopic heater for gutta-percha. 
Fir,. 315 




Flagg's gutta-percha softener and tool heater. 



316 



PLASTICS 



the cavity formation may be varied somewhat from that for gold or 
amalgam. 

When the cavity has been prepared for the filling it is often found 
advantageous to moisten the walls with eucalyptol or cajuput oil. 



Fig. 316 




Electro-Dental Manufacturing Co. 
Trimmer for gutta-percha heated by electricity. 



This will soften the gutta-percha somewhat and add to its adhesive- 
ness. The gutta-percha should then be made plastic by passing it 



GUTTA-PERCHA 317 

over the flame or by placing it upon one of the specially designed 
heaters. It is often convenient to use the different varieties of gold 
annealers for this purpose. The heater most commonly used is made 
of steatite, and is shown in Fig. 314. The heat-retaining properties of 
soapstone, together with its desirable surface, make it as good a heater 
as any yet designed. After the gutta-percha has been softened it may 
be rolled into a single piece of a shape convenient for insertion, and 
packed in place with cool instruments. It may also be inserted 
gradually by adding piece after piece to the walls of the cavity and 
the already inserted gutta-percha. This method is usually better if 
there is not easy access or if there is danger of compressing the pulp 

Fig. 317 




Hot air syringe. 

or forcing medicinal agents through the apical foramen in devitalized 
teeth. After the cavity is filled it should be trimmed to shape with 
the ordinary plastic instruments by warming them to a point where 
they will cut through the gutta-percha without tending to draw it 
from the cavity. The instruments should be heated gently in the 
flame or in one of the heaters, as shown in Fig. 315. Several instru- 
ments which are heated by the electric current have been designed for 
trimming gutta-percha (Fig. 316). They are very useful for some 
operations, but, as a general rule, a little more clumsy than the regular 
plastic instruments. 

For finishing some gutta-percha fillings, where it is not necessary to 



318 



PLASTICS 



direct the blast of hot air against the soft tissues, the electric hot air 
syringe (Fig. 317) is very useful. It may be used in heating crowns 
which have been set temporarily with gutta-percha. With this instru- 
ment a blast of hot air may be directed against a porcelain crown, 
having a metal post, until it can be easily removed. When the hot 
air syringe is used to soften the gutta-percha only very sharp instru- 
ments should be used to trim off the excess, or the mass will be moved 
in the cavity. In general, gutta-percha should not be warmed after 
being inserted into the cavity, but should be chilled and trimmed with 
warm, sharp instruments. Gutta-percha may be trimmed into shape 
with the ordinary plastic instruments by warming them. It is better, 
however, to use more of the sharp-edged instruments, such as carvers 
and excavators. Heat may also be conveyed to large masses of gutta- 
percha, especially in removing crowns set with this material, by heating 
a larger burnisher and placing it upon the mass of gutta-percha. It is 
still better to place a good-sized piece of copper upon an instrument 
handle (Fig. 318). 

For the use of gutta-percha as a root canal filling see Chapter XIV. 

Fig. 318 




Gutta-percha with Other Materials. — Temporary Stopping. — This 
material differs from ordinary gutta-percha chiefly in its working 
qualities. It is prepared from both white and pink gutta-percha by 
the addition of some of the gums or waxes, together with other materials, 
such as certain sulphates, carbonates, or oxids. 

It is also made without the gums or waxes. It may be prepared 
so that it exhibits considerable adhesiveness by the addition of 
Burgundy pitch. These preparations are designed for a variety of 
purposes; their principal use is the stopping of excavated cavities for 
a short time. 

As the name implies, they are intended for work more temporary 
in nature than that which would require gutta-percha. As a result 



TIN AND ITS COMBINATIONS 319 

of their use for the most temporary operations, many of the qualities 
of other plastics have been given to this material by the addition of 
some of the above-named materials. Many of these preparations 
remain quite hard in the mouth, although some are less resistant than 
gutta-percha, and more plastic in every way. The most conspicuous 
differences between them and gutta-percha is that they are generally 
softened with lower heat 'and have little or none of the toughness and 
stringiness so prominent in gutta-percha. Their manipulation is similar 
to that of gutta-percha. 

Gutta-percha and Gum Shellac. — Gutta-percha may be mixed with 
gum shellac to make a stiff and yet tough material, for use largely as a 
base-plate. It may be used, however, for a variety of purposes where 
other forms of gutta-percha would scarcely be rigid enough. 

Gutta-percha with Medicinal Agents. — Such substances as oxid of 
copper, finely divided tin, silver nitrate, eucalyptol, creosote, etc., are 
often incorporated with gutta-percha. It is claimed by the makers 
of some of the gutta points supplied for filling root canals that the 
process of refining the crude gutta-percha removes a natural oil which 
should be supplied before the points are suitable for use. The addition 
of some of the oils in such cases not only supplies what it is asserted 
to have been removed, but for a time makes the points more or less 
antiseptic. 

The other substances mentioned are less frequently added to gutta- 
percha. The salts of copper and finely divided tin can be advanta- 
geously incorporated when it seems imperative to leave gutta-percha 
in the mouth exposed to the saliva for some time. The use of gutta- 
percha with either of these materials is limited to remote parts of the 
mouth on account of their color. The manipulations of these mixtures 
is similar to that of gutta-percha alone. AVhen these two materials, 
or other similar substances, are combined with gutta-percha, the result- 
ing product is not unlike it, but some of the properties of the combined 
substance are added. 

TIN AND ITS COMBINATIONS 

Another material which hardly belongs under the head of plastics 
is tin. It possesses some plastic properties, however, which make its 
brief consideration in this chapter admissible. Tin as used by dent- 
ists is a white metal with a brilliant luster. It is quite malleable, 
although less so than gold. It is not very tenacious, comparing with 
gold in the ratio of two to seven. Its melting point is very low, and 
its annealing point likewise low, annealing usually being accomplished by 
keeping the tin under boiling water for five or ten minutes, and allowing 
it to cool there. Like gold, it is free from change in volume due to chemi- 
cal change, its only change in volume appearing with thermal variations. 



320 PLASTICS 

It is an inferior conductor of heat and electricity. In an alloyed or 
finely divided state it tarnishes readily, although when used as a coating 
for articles made of iron, etc., or in ingot form, it remains of a compara- 
tively bright color. 

Like gold, it can be welded in the cold state. This latter property is 
still questioned by many who hold that its use in dentistry as a fill- 
ing material is made possible through a mechanical entanglement of 
the pieces of tin used. This supposition, however, seems to be based 
upon observations made on tin in the form of foil. If the more 
recently introduced tin shavings are used, while freshly cut, the cohe- 
sive property appears in an unmistakable manner. This cohesive 
property seems to be lost somewhat with the rolling and beating 
necessary to produce the tin in sheet form. Like gold foil, its cohesive- 
ness is lost, either by a union with or a condensation upon its surface 
of substances often present in the atmosphere, and this cohesiveness 
cannot be restored by heating. 

It may be seen that tin resembles gold more closely in many of its 
properties than it does the other filling materials. Probably those who 
have been most successful with it have treated it in much the same 
manner as non-cohesive gold. Its use alone or in combination with 
gold foil seems to be indicated in places where a permanent operation 
is desired, but which cannot be well done w T ith gold foil because of lack 
of access. In very inaccessible places the plastic nature of tin usually 
permits of a much better adaptation to the margins and walls of the 
tooth than gold foil. Tin is generally selected for cases in which gold 
foil could be employed were it not for the difficulty of access and the 
fact that better results are obtained when some tin is used in connec- 
tion with the gold. Some, however, use it in cavities of easy access 
because they believe it has great preservative qualities. Those who 
believe most strongly in its preservative qualities often practise little 
or no extension to areas of relative immunity, and yet their success 
with tin is as great as that of those who do. Such successes may be 
attributed partly to the plastic nature of tin and its consequent ready 
adaptation, but the consensus of opinion would probably favor the 
theory that the tin possesses some inherent preservative qualities. 

There are few who do not feel that tin has some property, peculiar 
to itself, of inhibiting caries, and yet there seems to be no definite 
understanding of the process. 

Dr. W. T. Miller 1 has stated that tin is neither antiseptic nor thera- 
peutic in action; Marshall, 2 that it is decidedly antiseptic when oxidized; 
and Ambler, 3 that " the filling itself will prevent caries, but the oxid of 
tin formed in the mouth affords an additional barrier." Thus, it 
may be seen that there are a variety of views as to how tin saves teeth. 

1 Dental Cosmos, vol. xxxii, p. 714. 2 Operative Dentistry, p. 286. 

3 Tin Foil and its Combinations, p. 42. 



TIN AND ITS COMBINATIONS 321 

Many have observed that not all tin fillings were oxidized. Neither 
had any other salt formed to any appreciable extent, and yet the tooth 
tissue was protected equally well. Probably most tin fillings which 
have not turned black after some time in the mouth have been located 
where there was abrasion of its surface, although there seems to be 
some difference in the action of the oral fluids upon this material. 

The preservative qualities of tin claimed by so many seem not 
entirely dependent upon either the antiseptic action of tin or its salts, 
but also upon a change produced in the tooth tissue which is decidedly 
antagonistic to the progress of caries. Those who have examined cavi- 
ties which have had tin fillings for some time almost invariably 
observed a tissue change which in the case of other filling materials 
occurred only when alloys containing large percentages of copper were 
used. 

Tin may be used either alone or with gold. Many operators employ 
it in the form of foil or shavings to fill the cervical portion of proximate 
cavities in remote parts of the mouth or at least obscured from view. 
In such cases it is usually manipulated like non-cohesive gold, and is 
used as a base for the remainder of the filling, which may be either 
non-cohesive or cohesive gold. It possesses too much flow for a suc- 
cessful base for gold fillings when much force is to be applied to the 
filling, and should be used in this manner only when the force of occlu- 
sion is distributed over nearly all the teeth. 

Tin foil may be used with gold in the form of a "tin-gold," a sheet 
of tin and a sheet of gold being rolled together. This combination 
may vary, some operators preferring slightly more of one metal than 
the other. It may be folded or crimped to make a material which 
works in slightly different fashion, but in either case the tin and gold 
are inserted together. 

"Tin-gold" is usually made from the thinner tin foils and non- 
cohesive gold foil, No. 4 being very good for both. It is inserted in 
the same manner as non-cohesive gold, and when finished possesses 
many of the properties of that material, but is more plastic, a poorer 
conductor, different in color, and somewhat weaker at the time of 
insertion. Many have observed that "tin-gold" fillings after some 
time have changed in character. Instead of being relatively malle- 
able as when inserted, the mass seems to form a typical gold-tin 
alloy by becoming harder and more brittle. There is good reason 
to believe that this is what has taken place. 

Recent investigations tend to show that many metals will alloy with 
other metals, if they are pure, when brought into intimate contact in 
the absence of heat. As long ago as 1878, Professor Spring, of Liege, 
made studies of the different methods of producing alloys by com- 
pressing the constituent metals, and was able to produce certain 
alloys in the absence of heat that possessed physical properties quite 
21 



322 PLASTICS 

analogous to those produced by heat. Spring's studies have since been 
extended and his observations have been confirmed by others until 
these phenomena are looked upon as comparatively ordinary occur- 
rences. 

Tin-gold may be used in places where either tin or non-cohesive gold 
are used. The insertion and finishing of the filling are accomplished 
in the same manner as non-cohesive gold or tin. 

Some operators have used tin foil in combination with amalgam with 
a degree of success, but it has disadvantages when used in this manner 
that do not occur when it is employed with other materials. It will be 
recalled that change of volume in filling materials is either physical, 
due to thermal variations, or chemical, due to the union of two or 
more substances. Tin alone is subject to physical change in volume 
only, and this is probably also largely true when it is used as the base 
of a gold filling. Likewise probably little chemical change in volume 
occurs during the early stages of a tin-gold filling, although it may be 
considerable during the later stages. 

When amalgam is used as a covering for tin fillings, as is done by 
some operators, a contraction of the whole mass is likely to result if 
the amalgam has been made from a low percentage silver alloy, but not 
so much so if a rapid setting alloy has been used. It would seem that 
there is little or no occasion for the use of amalgam with tin, although 
some regard it a useful combination. When amalgam is used with tin 
it is inserted as a covering for it so that the surface of the filling will 
be harder than it would be if made entirely of tin. Such operations, 
however, are confined to remote parts of the mouth. 

LININGS FOR CAVITIES. 

In the practice of dentistry it often becomes necessary to line the 
walls of a cavity or to coat the surface of teeth with substances which 
are poor conductors or will prevent the irritant action of certain filling 
materials, such as some of the cements. Of the materials available for 
this purpose the various varnishes are most used. They are solutions 
of gums and resins in alcohol, chloroform, and ether, which can be 
applied in a film as a protective to the walls of cavities or surfaces 
of teeth. 

Sandarac in alcohol, and hard Canada balsam, copal, or damar in 
ether are among the more common of these materials. 1 The prepara- 
tion known as Kristaline, a solution of trinitrocellulose in anhydrous 
amyl acetate (Kirk), is also used. Virgin rubber or gutta-percha dis- 
solved in chloroform may be used in the same manner; in most cases 

1 For some formulae of these varnishes the reader is referred to Dr. Prinz's Dental 
Formulary. 



LININGS FOR CAVITIES 323 

the latter two are less desirable, as they are less adhesive. Silver 
nitrate has been extensively used as a lining for cavities, especially in 
cases of carious tissue whose removal was impractical. It must not 
be regarded as a non-conductor in the sense that the varnishes are, 
however, because it is reduced to metallic silver when brought in con- 
tact with organic substances, hence the dark color. These different 
linings, especially the gums and resins, are of great value in preventing 
galvanic disturbances and rapid conductivity of thermal impression 
produced by amalgam. They are also useful under gold fillings and the 
full and partial caps often placed upon teeth. They are also useful in 
preventing the irritant action of both the basic zinc phosphates and 
the silicate cements. In the earlier stages of the setting of either 
class free acid is likely to form, while during the stages of disintegra- 
tion acid salts are apt to occur in contact with the dentinal walls if 
a lining has not been used. 

Formerly some of these linings were used to prevent the discoloration 
of tooth tissue by amalgam, but this is not necessary with the more 
recent ones. It is, however, a good precaution to take if copper amal- 
gam is used. These linings may be applied to the walls of the cavity 
or surfaces of a tooth with the ordinary pliers and a bit of cotton, or 
directly with any small instrument. Before their application, the 
surface should have had the regular treatment given to cavities pre- 
paratory to filling and should have been wiped with a solution of 
sodium carbonate to remove traces of greasy substances. After the 
lining has been applied it should be allowed to stand until the greater 
part of the volatile portion has disappeared and the lining is quite hard. 



CHAPTER XII 
COMBINATION FILLINGS 

By MARCUS L. WARD, D.D.Sc. 

A careful study of the materials available for use in filling teeth shows 
that no one of them quite meets all the demands of modern dentistry. 
Some possess artistic qualities but lack strength. Others that possess 
the best strength are the farthest from nature in color. This is also true 
in regard to their destructibility in the oral media. Some are wholly in- 
soluble, while others are quite soluble in saliva, products of fermentation 
and certain food substances. Some materials are excellent conductors, 
while others are very poor ones. One or two are liable to considerable 
alteration in volume due to chemical change, while others are only sub- 
ject to change in volume due to thermal changes, one or two possessing 
a very small co-efficient of contraction and expansion. 

The alloys and cements now in use represent attempts to combine the 
desirable qualities of several materials in one product. These products 
often show that a material with only one desirable quality and several 
undesirable qualities may be introduced as a filling provided the former 
is pronounced. Even the most skilful makers have not yet succeeded in 
producing a material even approximately suitable for use alone in all cases. 

A filling material should be indestructible in the oral media, should 
approximate the color of the teeth, be free from contraction and ex- 
pansion after being made into fillings, should resist attrition and the 
force of mastication, be a poor conductor, easily manipulated, and quite 
adaptable to the walls of a cavity. Thus the requirements for a dental 
filling material are enormous and out of proportion to the demands 
made upon most materials in use in allied sciences. 

There is a constant desire that a filling material should possess one or 
more additional qualities and an increasing tendency to combine two 
or more materials to obtain the quality sought. The zinc phosphate 
cements have many excellent qualities and are almost invaluable. Their 
one good quality above all others is the property of adhesiveness, a 
quality sought but practically absent in all other filling materials. They 
are generally manipulated with ease, their color is good, and under 
proper handling they are relatively free from contraction and expansion, 
but they are not indestructible in the mouth. Gold has many excel- 
lent qualities, being strong, wholly indestructible in the mouth, and free 
from contraction or expansion caused by chemical changes. It is adapt- 
(324) 



COM BIN A TION FILLINGS 325 

able to many cases, but its color is poor, its insertion is tedious to both 
operator and patient, and it is an excellent conductor. Amalgam may 
be similarly criticised. While it may be inserted in places inaccessible to 
gold and last longer than most cement fillings, as a whole its qualities 
are poor when compared with the ideal standard for filling materials. It 
is almost but not entirely indestructible in the mouth. Its strength is 
indefinite. It is subject to chemical change in volume after insertion. 
Its color is poor and it is a good conductor. Certain of these objection- 
able qualities are very conspicuous when these fillings are used alone or 
in places where another filling material is indicated. For example, the 
examination of a large number of amalgam fillings in occlusal cavities 
will show more imperfect edges than in the case of fillings of a similar 
shape located on the buccal or proximal surface. The difference be- 
tween these classes of fillings is due to the fact that one class is sub- 
jected to stress and the other is not. 

Even when strongest, amalgam is relatively brittle and the change in 
volume is usually sufficient to cause fracture of the amalgam when in 
the course of time it is no longer supported by the cavity margins and 
stress is applied. Similarly located gold fillings do not show the differ- 
ences noted with amalgam, as gold is not brittle, and also remains more 
constant in volume. When placed against a margin it does not rise up 
above it nor shrink below it, as do most amalgam fillings. The deduc- 
tion seems to be that of the two materials, gold is much better for loca- 
tions where stress is applied. 

If a number of proximal gold or amalgam fillings be examined, the 
metal is usually found to show through the enamel, oftentimes conspicu- 
ously, on the buccal or labial side. This is particularly true when the 
cavities are quite deep. In such an examination, however, a few fillings 
are usually found near the surface which do not appear as dark as some 
others. Closer examination shows that some of the light-colored cements 
have been placed between the filling and the wall of the cavity. There can 
be little doubt but that the combination of the two filling materials has 
brought about a better result than one material could do. Thus, the 
adhesive quality of the cement may be utilized to make metal fillings 
more sightly as well as to strengthen the frail walls of such cavities. 
For this reason it is often desirable to combine in one filling two or 
more materials. It is the careful selection of filling materials and the 
ingenuity in combining them that saves the most teeth. 

Some seem to adhere to the idea that a material adapted for one place 
is equally adapted for others, and that combination fillings are resorted 
to because they are easier made than fillings of one material. Such is 
not true. If an operator gives his patients his best services he will 
make the same effort to combine the qualities of different filling materials 
that the makers of these products make in combining the qualities of 
different substances for a single filling material. 



326 COMBINATION FILLINGS 

It may be said truthfully that an operator's services may be measured 
only by his ingenuity in carrying to completion the plan adopted by 
the makers of filling materials. In this chapter only the mechanical 
operation of inserting the filling will be considered. All operations 
upon the pulp and root canals will be eliminated and the teeth will be 
considered ready to receive fillings. Not all combination fillings will be 
described. Only those most important will be considered, leaving 
those of lesser importance to the ingenuity of the operator. 



CEMENT (ZINC PHOSPHATE) AND AMALGAM 

This combination is one of the oldest and has been most serviceable 
in saving teeth that would otherwise have been crowned or lost. 
Originally the combination was employed in cavities where the interior 
of the cavity was much larger than the orifice. Such cavities are most 
frequent on the occlusal and proximal surfaces of the teeth. Many 
cases are seen where little but the enamel is left, which, when supported 
by an adhesive material, will withstand the ordinary stress of mastication. 

Fig. 321 shows an occlusal cavity of this kind, which consists princi- 
pally of a shell of enamel. To open such a cavity until there were no 
undercuts would obliterate the occlusal surface, while to fill it with a 
non-adhesive material would result in the breaking down of the over- 
hanging ledges of enamel under the ordinary stress of mastication. It 
may be recalled in this connection that enamel is much weaker than 
dentin, that it requires a piece of dentin approximately y-Q inch thick to 
sustain the force of mastication in the molar region, and that no strength 
is added to the tooth by metallic fillings, the inlays excepted. Hence, 
filling such cavities with amalgam or gold alone is folly. 

The combination of an adhesive material with a metal, however, gives 
an operation which often withstands the work of mastication for years. 
There are two methods for combining cement and amalgam. The first 
consists, in occlusal cavities, of filling the entire cavity with cement 
mixed to a putty-like consistency and allowing it to harden so that it 
may be cut with sharp instruments without moving its body and then 
cutting into it, a cavity with parallel walls of the size of the orifice of 
the cavity. Such a filling has the appearance of an amalgam filling, but 
it is in reality a cement filling with a veneer of amalgam, which protects 
the cement from the solvent action of the saliva and from becoming 
abraded by attrition. In large proximal cavities especially, where the 
pulp has been removed, a.similar procedure may be pursued to advan- 
tage. A cavity such as shown in Fig. 319 may be filled with cement and 
made to appear as Fig. 320. 

As may be seen, the part of the cavity left to be filled with amalgam 
is really a veneer covering the proximal and occlusal portion of the 



CEMENT AND AMALGAM 



327 



cavity. In these cases the cement forms a support for the frail walls 
which a metallic filling could not supply. Cement must not be used in 
too great quantities if the best results are to be obtained. 

Amalgam in thin layers will not withstand the force of mastication 
unless it has been packed into the cement while soft, thus uniting the 
amalgam to the cement. This constitutes another method of combining 
amalgam and cement in the form of an inlay, and is known as an 
amalgam inlay. The popularity of the inlay method of filling teeth 
seems responsible for the wide use of this combination. 

In large occlusal cavities such as shown in Fig. 321, the cement should 
be mixed to a consistency suitable for setting inlays and carried to the 
cavity with a Spalding loop (Fig. 322) or other suitable instrument and 
teased over the entire surface of the cavity. 



Fig. 319 



Fig. 320 



Fig. 321 





Devitalized molar tooth with 
cavity outlined. 



Molar tooth devitalized 
with cavity outlined and 
cement in place to be covered 
with amalgam or sold. 



Large occlusal cavity par- 
tially filled with amalgam 
and soft cement showing soft 
cement oozing out of cavity 
at margins. 



Amalgam which has been previously mixed and kept moving by the 
assistant so that it will not become too stiff is now packed in large 
pieces in the bottom of the cavity from the centre to the sides, allowing 
the excess cement to flow out of the cavity (Fig. 321). Care must be 
exercised not to leave a visible layer of cement between the amalgam 
and cavity margin, or the cement will dissolve out. The amalgam 
should be carefully finished to the edges of the cavity, so as to cover 
the cement as nearly as possible. The cement is usually reduced to a 
very thin layer by this method of insertion, although a sufficient amount 
remains to unite the cavity wall to the amalgam, thus supporting the 
frail walls in a manner impossible with amalgam alone. 

In filling proximo-occlusal cavities which have frail walls the same 
technique may be pursued, except that the thin cement should not be 



328 COMBINATION FILLINGS 

placed along the border of the cavity next to the matrix and the amalgam 
should be packed along this border, first causing the excess cement to 
flow out of the occlusal portion of the cavity. The amalgam and cement 
method has been used with advantage in highly sensitive cavities where a 
proper retaining form could not be obtained. Fig. 320 shows an approxi- 
mal cavity which might be filled with amalgam and soft cement, often 
giving good results. Such operations, however, are not always the best 
possible, but perhaps the best under the circumstances. The so-called 

Fig. 322 



Spalding loop for carrying cement. 

amalgam inlay has also been used successfully in building up broken- 
down molars and bicuspids. There is a tendency to use soft cement 
under all large amalgam fillings, regardless of the necessity for an 
adhesive material to strengthen the tooth or to retain the filling. The 
lessened conductivity of the combined cement and amalgam seems in 
many cases to warrant the use of the two in preference to amalgam 
alone, while in other cases the improvement in the color of the tooth is 
quite marked. 

CEMENT AND GOLD 

Cement and gold may be used in posterior cavities in much the same 
manner as has been described for amalgam. Gold, however, cannot be 
packed into soft cement in the same manner as amalgam. The class 
of cavities selected in the posterior part of the mouth to be filled with 
gold, as a rule, do not require the adhesive material, and besides it is 
almost impossible to pack gold into soft cement anywhere except on the 
floor of the cavity. Filling occlusal and proximo-occlusal cavities par- 
tially full of cement (Fig. 320) and allowing it to harden is commonly 
practised, since it is comparatively easily done and the filling so inserted 
has the same advantages with gold as it has with amalgam. Cement 
inserted in this manner must be allowed to harden sufficiently to resist 
the impact of the mallet in condensing the gold without being disturbed, 
otherwise the gold will often become loose after the operation is partially 
completed. Some operators use a small amount of rapid-setting soft 
cement in the base of all cavities to be filled with gold. In such cases 
some of the so-called "sponge" golds are usually employed to pack a 
quantity into the soft cement, after which, allowing the cement to 
harden somewhat, more of the " sponge" gold or some of the foil golds 
may be built upon the gold which has been packed into the cement. 

Care must be exercised to use sufficient gold so that the soft cement 
will not ooze through the gold, thus destroying the cohesiveness of its 



AMALGAM AND GOLD 329 

surface. The same care should be exercised not to use too much cement, 
but only enough to fasten the gold to the surface of the cavity. This 
method of combining gold with cement will be found useful in the 
anterior teeth and the bicuspids where a dark area is likely to be pro- 
duced by the metal underneath thin layers of the tooth structure. If a 
light-colored cement is used, the effect is often much better than it other- 
wise would be. Cases of hypersensitive dentin often present compli- 
cations which make it necessary to resort to cement for anchorage. It 
may not be necessary for appearance, nor always necessary to gain 
strength, but it may be the only means of securing anchorage. This is 
oftentimes true in the teeth of young patients. 

Teeth that have been somewhat discolored may often be made much 
lighter by lining the cavity with a light-colored cement before inserting 
gold. Cavities in central incisors, having frail enamel walls that were 
in the past frequently filled with cement and gold, and would still be 
filled to advantage that way if gold were to be used, would at the 
present time preferably be restored by most operators by the porcelain 
inlay. In fact, the whole field of operative dentistry has been so 
changed by the introduction of porcelain and gold inlays and silicate 
cements that the practice of filling such cavities with cement and gold, 
amalgam and gold, or cement, amalgam, and gold, has become almost 
obsolete. 

AMALGAM AND GOLD 

Amalgam and gold have been used to advantage in many places, 
principally, however, in proximal cavities in bicuspids and molars which 
involve more or less of the occlusal surface. Before the advent of gold 
and porcelain inlays and silicate cements, gold was used to cover amal- 
gam on the buccal surfaces of the bicuspids and molars much more 
than now, although some operators still adhere to this method in prefer- 
ence to the more recent ones. The filling of mesio-approximal cavities 
in upper bicuspids and molars which involve considerable of the buccal 
surface, even with the lighter-colored amalgams, is regarded as especially 
poor practice by most operators, since there are a variety of combina- 
tions which may be used to prevent the exposure to view of the 
unsightly amalgam. Many enthusiasts hold that such cavities can be 
filled with the silicate cements, while the more conservative claim that 
they can better be filled with amalgam and gold. 

Fig. 321 shows a cavity which in most cases is extremely difficult to 
fill with gold foil because it is so wide at the cervical portion and 
extends some distance below the gum line. It is equally difficult to 
keep such a cavity perfectly dry during the insertion and finishing of a 
silicate cement and these fillings are of little value unless they are kept 
free from moisture during the first few hours of setting. If such cavities 



830 COMBINATION FILLINGS 

do not extend too far laterally it is often better to cut them open to 
receive either a gold or porcelain inlay, but in many of them caries has 
proceeded too far to admit of either. Such cavities can be filled with 
amalgam and the amalgam allowed to harden, after which the portion 
exposed to view may be cut away and filled with gold. 

When gold and amalgam are used in combination it often becomes 
necessary to make a retaining form in the amalgam for anchoring the 
gold. There is no union between the two after the amalgam has hard- 
ened, and often such cavities can be filled only by gaining a reten- 
tion somewhat remote from the place where gold is to be placed, thus 
requiring the retention for the gold to be placed in the amalgam. 
Some operators use amalgam and gold to fill occlusal cavities similar 
to the one shown in Fig. 321. The advantages of this combination, 
however, over that of cement and gold in such places are not very 
apparent. Many in the past have considered it necessary to place 
cement under all amalgam fillings which were to have gold in com- 
bination, in order to increase the strength and to diminish the amount 
of discolored tooth tissue from the amalgam. 

The tendency seems to be to use cement under all large amalgam 
fillings whether gold is used or not, that there shall be increased 
strength ; but there seems little or no thought of preventing discoloration 
of tooth tissue, as with proper use of modern alloys this is extremely 
rare. Gold has been used with amalgam by packing the gold into the 
amalgam while soft, but the operation seems to be about obsolete. 
Recent studies of amalgams seem to make it clear that like other crys- 
tallizing bodies they should not be disturbed during the setting process, 
more than is necessary when placing gold over soft amalgam. Special 
emphasis has been placed upon using steady but firm pressure in pack- 
ing amalgam and allowing it to lie still until hardened. 



GUTTA-PERCHA AND CEMENT 

Gutta-percha has unquestionably had its field of usefulness lessened 
materially within the last few years. It has been used in combination 
with cement, gold, and amalgam, and served a very useful purpose. 
The demands of the profession, however, for better hygienic conditions 
in the mouth has practically eliminated it except for the most temporary 
operations. Gutta-percha fillings which are expected to remain for 
months are fast being regarded as bad practice, regardless of whether 
the gutta-percha is in combination with other materials or not. The 
recent demands of orthodontists for a harder material with a well- 
restored contour for proximal cavities has also served to lessen the 
amount of gutta-percha used. 

Gutta-percha may be used in combination with cement by placing 



BASIC ZINC PHOSPHATES AND SILICATE CEMENTS 331 

it at the cervical third of proximal cavities where cement is often dis- 
solved out first, but the tendency is to refrain from inserting gutta- 
percha where it is exposed to the oral fluids. This has been one of 
the methods employed to meet the requirements of some of the per- 
plexing operations on the deciduous teeth. Many operators adhere to 
the use of oxyphosphates of copper for all operations on the deciduous 
teeth. Others follow the advice of many orthodontists by caring for the 
deciduous teeth with amalgam alone or in the form of an inlay with 
oxyphosphate of copper for the cementing medium. A few use inlays 
in the deciduous teeth, but those who use gutta percha appear for the 
greater part to be doing so with an apology. 



CEMENT AND ALLOY 

A mixture of thin cement and alloy fillings has been recommended 
by some for operations in remote parts of the mouth where it is desired 
to prolong the durability of a cement filling. The main object of the 
alloy is to protect the cement somewhat from the fluids of the mouth. 

With the development of the inlay method a tendency has developed 
to use cement and alloy in the form of an amalgam inlay (Fig. 321), 
instead of in this combination. If cement and alloy are to be used 
the cement should be slow setting. A comparatively slow setting cement 
is mixed to a creamy consistence and the alloy then worked into it to 
the desired consistence. 

The advantages of cement and alloy over amalgam are adhesiveness 
and non-conductivity. Its advantages over cement are durability and 
hardness. This combination has been of service in restoring badly 
decayed teeth and in some sections still seems to be in favor, but, like 
gutta-percha, it is being eliminated by the recent demands for better 
oral hygienic conditions. 

BASIC ZINC PHOSPHATES AND SILICATE CEMENTS 

This combination is of comparatively recent origin and has been 
found necessary to carry out the insertion of the silicate cements. One 
of the first observations in the use of the silicate cements was that they 
were irritant to the pulps of the teeth. This is also true of the basic 
zinc phosphates, especially when the acid is present in comparatively 
large quantities, as when the cement is mixed to a creamy consistence 
for retaining inlays, bands, crowns, etc. There is, however, more irrita- 
tion from the silicate cements as at present introduced than there is 
with the basic zinc phosphates. To correct this to some extent, many 
have advocated placing a layer of basic zinc phosphate which had been 
mixed rather stiff along the pulpal wall of the cavity. 



332 COMBINATION FILLINGS 

As a rule, cavities requiring a lining material have only a thin lamina 
of dentin over the pulp, and care must be exercised not to use the basic 
zinc phosphate so stiff that much pressure is required to place it. It is 
better, however, to have the cement as basic as possible, and get the 
minimum of pressure in placing and the required adhesion. It is often 
best to precede the insertion of the basic zinc phosphate with a layer 
of one of the lining varnishes, while at other times the lining varnish 
may be used and the basic zinc phosphate dispensed with. The greater 
adhesion of the basic zinc phosphates over the silicate cements is keeping 
them in favor for filling undercuts and the deeper portions of all cavities 
regardless of whether it is actually necessary or not. 

The basic zinc phosphates will unquestionably add more to the 
strength of teeth with frail walls than the silicate cements now in use, 
although the latter are not entirely devoid of adhesion. Owing to the 
uncertainty of the solubility of the silicate cements, the tendency is to 
leave more unsupported enamel when using it than when using other 
materials except the basic zinc phosphates. 

Cavities that have ordinarily been extended to areas of relative immu- 
nity for the reception of other materials are being filled with basic zinc 
phosphate and silicate cements without such extension. Just what 
the judgment of the profession will be regarding this practice cannot be 
stated, but it is probable that more failures will attend the use of the 
silicate without extension than would occur from a dissolving of them 
and the result will be more extension of the cavities. 



CHAPTEE XIII 

RESTORATION OF TEETH BY CEMENTED INLAYS 

By W. A. CAPON, D.D.Sc. 

This branch of operative dentistry has for many years been an 
important factor in the preservation of teeth, particularly those of poor 
structure precluding the use of ordinary means of restoration through 
the use of mallet or hand pressure gold fillings. The term inlay, accu- 
rately speaking, may be applied to any substance placed in the cavity as 
in one piece and held in position by an adhesive cement, but porcelain 
and gold are the generally accepted materials when "making an inlay'* 
is spoken of. 

The process of making a porcelain inlay is practically the same at 
present as when first introduced some twenty years ago, but the advent 
of the casting machine for gold has revolutionized that work and made 
it possible for every dentist to make inlays in a scientific and practical 
manner and enlarge his usefulness as an operator to the advantage of 
all concerned. 

The desire for a more natural appearing material for tooth restora- 
tion existed many years before practical means were discovered, and 
much energy was expended toward making porcelain in some form fulfil 
that requirement. Pieces of porcelain matching the natural tooth have 
in times past been ground to fit the cavities and then cemented to place, 
but this class of work is hardly feasible except in labial cavities or some 
regular surface of the front teeth. Ready-made porcelain inlays have 
been kept in stock for years at the dental depots. They are in the 
form of rods in various shades and diameters, while others of different 
shapes and sizes are ground to fit the cavities and finally cemented in 
place, after which they are polished. 

Some, however, instead of being ground to fit the cavity, require the 
cavity to be ground to fit them (Fig. 323). 

Dr. Geo. H. Weagant, devised a set of instruments (Fig. 324) suitable 
for this process, consisting of five trephines of consecutive sizes, made of 
copper charged with diamond dust. These instruments are intended to 
cut pieces of porcelain out of an artificial tooth that matches the color 
of the natural tooth, and the cavity in the natural tooth is prepared with 
one of Dr. How's inlay burs (Fig. 325) corresponding in size to the trephine. 
This method has several serious objections, one of the principal being 
that, in order to give the cavity a circular shape, much tooth structure is 

(333) 



334 RESTORATION OF TEETH BY CEMENTED INLAYS 

usually sacrificed. Take for example the decayed spot shown in Fig. 326. 
This would have to be enlarged as in Fig. 326 b— -which is a serious 
objection. 

Fig. 323 

e © 0Q 

►00000 

§t*@0@©@© 
300000000 

)OOOoolQ8l0 

Porcelain cavity stoppers. 



Fig. 324 



Fig. 325 




© O w 



I 



s j 




Dr. Weagant's diamond trephines. 



Dr. How's inlay burs. 



Fig. 326 




As early as 1882 Dr. Herbert advocated glass 
fillings. These were made by taking impressions 
of the cavity in wax and making two moulds in 
some such material as plaster or asbestos. The 
ground glass was then flowed into the first mould, 
in which most of the shrinkage occurred. The 
a i) partly formed filling was then removed and placed 

in the second mould, when more glass was added 
until the filling was complete. Even with this crude method the results 
were fairly satisfactory, although the margins were far from perfect and 
the glass was permeable to such an extent as to blacken ; nevertheless, 
fillings were made that preserved the teeth for years. 

In 1887 Dr. C. H. Land made mechanically perfect edges possible by 
devising the metal matrix. Dr. Land used both gold and platinum, but 
found the latter preferable, as platinum could be adapted with a facility 
equal to gold, and allowed the use of high fusing tooth body much 
stronger and less likely to deteriorate than bodies capable of being fused 



RESTORATION OF TEETH BY CEMENTED INLAYS 335 

on gold, which of necessity requires so large a percentage of glass that 
they, like the fillings of Herbst, lacked permanence of gloss and color. 

From Land's discovery dates all effective porcelain fillings. Before 
this, pieces of porcelain had been ground to fit labial cavities with fair 
results, but the accurate adaptation of porcelain to proximal cavities 
was impossible until the metal matrix was evolved. 

It is claimed that inlays are idealistic in their results, and this is 
undoubtedly true, providing certain considerations are adhered to. But 
it being impossible to make one material perfect under all circumstances, 
it is then necessary to resort to a combination that will lead to the best 
results. Porcelain inlays are ideal because when properly made they 
restore the tooth more closely to its original and natural appearance 
than gold or any other material. Its resisting qualities are much inferior 
to gold, therefore its value decreases if appearance and artistic quality 
are not first considerations. Gold in inlay form is then used, which 
justifies us in classifying the cemented inlay as an ideal means of 
restoration, unequalled and unchallenged. 

In other words, the use of porcelain for anterior teeth and gold for the 
wear and tear of posterior teeth have all the characteristic of ideal fillings 
because they exclude germs of decay and preclude from growth those 
that enter. An inlay is a non-conductor of heat; it adheres to cavity 
walls, its manipulation is easy to the patient and conservative of tooth 
structure. It has : 

1. Resistance to wear of mastication. 

2. Resistance to the action of oral fluids. 

3. Harmony of color when porcelain is used. 

4. Exclusion of bacteria and preclusion from growth of those that 
may enter the margin. 

5. Non-conductivity of heat and electricity. 

6. Manipulation easy to patient. 

7. Manipulation easy to operator. 

8. Manipulation not destructive of healthy tooth structure. 

9. Re-insertion with little preparation. 

10. Duplication, which means that in many (cavity preparation) 
instances a duplicate is made and reserved by the operator for use in 
case of accident to the original. 

The success of an inlay will depend largely upon four points of differ- 
ence between its cavity preparation and that for those of foil, gutta- 
percha, amalgam, or cements, viz., upright walls, square enamel edges, 
no undercuts, and depth. The walls being perpendicular or nearly so, 
allow the easy withdrawal of the metal matrix either of platinum or gold, 
or in the case of the impression for casting with wax or any material for 
the purpose of making a model. The enamel edges are made square 
so that the inlay will have no overhanging frail edges of porcelain. 

An undercut will prevent the easv removal of the matrix frequently 



336 



RESTORATION OF TEETH BY CEMENTED INLAYS 



distorting it, and when using wax not even the slightest undercut is 
permissible. In connection with porcelain, depth of cavity has much 
to do with retention in fact; it is more important than various keys and 
irregular forms advocated by many writers on this subject. Unfor- 
tunately we cannot always get sufficient depth, and, on the contrary, 
many cavities, when entirely cleared of decay, are too deep to obtain 
an unmutilated matrix particularly with platinum; however, when this 
condition exists it is an easy matter to reduce it by partially filling 
with cement or gutta-percha. 

The advantages of depth are retention, strength, through quantity 
of material and purity of shade by having sufficient volume of porcelain 
which assists materially in reducing the opacity caused by the cement. 

This rule pertaining to deep cavities has not the same value when 
applied to the cast gold inlay, and it is well to note that the same rules 
which apply to porcelain inlays are applicable to matrix gold inlays, 
excepting that point pertaining to shading, because cavities prepared 
for matrices have always the burnishing feature prominent, which means 
curves and all surfaces accessible to the burnisher. 

The following representations of various cavities in natural teeth 
where porcelain is indicated and applicable are shown with the same 
cavity prepared and ready for the matrix. By this means the student 
will readily note what is requisite and necessary without detailed descrip- 
tion and technical nomenclature. 



Fig. 327 



Fig. 328 



Fig. 329 






Figs. 327 to 334 show simple cavities, and m each case the border has 
been extended beyond the outline of decay, for the same consideration 



RESTORATION OF TEETH BY CEMENTED INLAYS 337 

with respect to extension is applied in this class of work as if the cavity 
were to be filled with gold. 

Fig. 330 Fig. 331 Fig. 332 






Figs. 335 and 336 are in the same class but are more difficult, for they 
have resulted from another cause, viz. , abrasion or erosion, and it is noted 
particularly because this condition is common, and the cavity prepar- 
ation much more difficult, The depth is insufficient and the margins are 

Fig. 333 Fig. 334 





never defined, which necessitates extensive cutting into hard and unusu- 
ally sensitive dentin, and as this kind of cavity is almost as common 
22 



338 



RESTORATION OF TEETH BY CEMENTED INLAYS 



in lower teeth the difficulty of preparation and general manipulation is 
increased. This applies to all labial cavities and is noticed more in 



Fig. 335 



Fig. 336 





porcelain operations, because when the cavity is ready the matrix must 
be held in position firmly, a procedure interfered w T ith by the lower lip 
and the saliva. The use of rubber dam is not desirable because it reduces 
the working space, but it has other advantages occasionally. 



Fig. 337 



Fig. 338 



Fig. 339 






Figs. 337 to 346 show cavities presenting greater difficulties both in 
preparation and general manipulation. Cavities in such positions 



RESTORATION OF TEETH BY CEMENTED INLAYS 



339 



must have plenty of space between the adjoining tooth, otherwise a matrix 
cannot be withdrawn or the finished filling inserted. Sometimes it is 



Fig. 340 



Fig. 341 





impossible to get sufficient space for drawing the matrix without dis- 
tortion ; in such instances the cavity is prepared with this point as a first 
consideration. Fig. 34(5 shows a cavity of this kind. If there is not much 



Fig. 342 



Fig. 343 



Fit;. 344 






difference in outline of the cavity labially or lingually, choose the labial 
side to extract the matrix; or if cutting the labial margins does not inter- 



340 



RESTORATION OF TEETH BY CEMENTED INLAYS 



fere with the welfare of the tooth, resort to this assistance in preference to 
difficulties of lingual matrix extractions. In Figs. 338 and 340 the matrix 
under ordinary conditions will be withdrawn lingually. Figs. 339 and 341 



Fig. 345 



Fig. 346 





show uncertain incisal edges which are reduced in Figs. 342 and 344; 
therefore the difficulties of drawing a matrix in this case are very much 
reduced, for the cavity is so large that working space is greatly extended. 
Large proximal cavities of Fig. 341 type, where the incisal edge is of 
greater strength and is retained, are very difficult and frequent. The 



Fig. 347 



Fig. 348 





matrix formation requires skill and patience, but the reward is dura- 
bility — for the inlay in this case is thoroughly protected and is rarely 
unseated. 



RESTORATION OF TEETH BY CEMENTED INLAYS 



341 



Figs. 347 and 348 show a cavity on the gingival border extending under 
the gum margin and involving a considerable portion of the tooth mesially 



Fig. 349 



Fig. 350 





and distally. It is a typical representation of this form of cavity and the 
position is one demanding a restoration with porcelain. The cavity 
walls are governed by its extent, for the matrix will warp if a strict 
rule of upright walls is carried out here. The cervical wall will not be 



Fig. 351 



Fig. 352 



Fig. 353 






at right angles to the pulpal wall or floor, or if so made- they cannot be 
of that form at the extreme mesial and distal border; therefore, in these 



342 RESTORATION OF TEETH BY CEMENTED INLAYS 

cavities strict adherence to a right angle upright wall is not possible for 
the best result. When the matrix is burnished it should be packed with 
gum camphor in preference to other materials recommended. It is not 
always possible to make a very extensive inlay of this kind of one piece, 
therefore it should be divided at the median line of tooth and two 
operations made. 

Figs. 349 to 353 represent extensive proximal cavities or fractures 
extending to the incisal edge, and at a position where porcelain is of 
great importance. The apparent insufficient anchorage deters many 
operators from using porcelain, and the preparation of these cavities is 
the cause of more different opinions than any other. It is claimed that 
without a key or step on the lingual surface porcelain will not be retained 
by the ordinarily prepared cavity, and unnecessary cutting of good tooth 
structure is taught with most deplorable results — in many instances, 
irregularity of cavity and its borders increase the matrix-formation 
difficulties, therefore a simple preparation is taken advantage of. With 
few exceptions the cavity can be prepared similarly to Fig. 342, defining 
the labial and lingual walls and anchorage increased by a groove with a 
round bur at the gingival border resembling a deep undercut, as for a 
gold rilling. Anchorage is also increased by grooving between the enamel 
plates at the incisal edge. The matrix must be burnished to these sur- 
faces, otherwise the value of the preparation is lost. The labial outline, 
Fig. 352, can be varied in many ways, but angles are to be avoided when- 
ever possible. Very often the corner is of the form of an irregular tri- 
angle tapering to a wedge point at the cutting edge. The porcelain at 
that point is very frail and will break, leaving an irreparable notch. 
To avoid this, cut an axial wall as in Fig. 353, and thus make a body of 
porcelain, giving strength at a weak point. This same cavity is sometimes 
so extensive that anchorage is made by wire pins or staples. In instances 
where the incisal section of the tooth has been lost by accident or decay, 
this process of retention is preferable and highly recommended for per- 
manency. Fig. 354 shows a central tooth, a matrix, and the porcelain 
section with wire anchorage. This case shows loss of one-fourth of the 
tooth and the cavity made by cutting the dentin to the required depth, an 
operation possible with few exceptions. The enamel edges are made true 
by a flat stone, after which the matrix is made of the walls and edges, and 
shown without a floor. The wire is iridioplatinum, gauge 24, made in the 
form of a staple or loop, and inserted while the matrix is in place; with 
these in position, porcelain in paste form is pressed over all and excess 
moisture is absorbed by holding a napkin or bibulous paper to its surface. 
The combination is carefully taken from the cavity and fused, thus 
forming a base with a wire loop or pins held securely without soldering. 
This foundation is now placed on the tooth and matrix edges thoroughly 
burnished, after which the operation is completed by repeated fusing. 
When the matrix is removed the contoured tip will resemble the third 



RESTORATION OF TEETH BY CEMENTED INLAYS 



343 



section of Fig. 354, and is ready for cementing. When the first porcelain 
is applied it will likely fill the loop, but this must not be corrected until 
after fusing, when the porcelain is easily broken away with blunt pliers. 
Frequently the staple or loop is inverted to suit conditions, but the form 
represented is the most durable in every particular. The difficulties 



Fig. 354 




of this operation are increased by the irregular form of fracture, for 
usually they extend lingually and frequently quite to the gum margin ; 
a restoration of this kind should not be attempted until the operator has 
had considerable practice, for the making of an incisal tip acceptably is 
one of the most difficult operations. 

Figs. 355 to 364 show cavities in biscupids and molars for porcelain 
inlays. The forms are very similar and directions for cavity technique are 
applicable in either instance. The value of porcelain in these positions 



Fig. 355 



Fig. 356 



Fig. 357 






is questioned because the force of contact is increased and the esthetic 
value is decreased. There are many exceptions, and the opportunities 
exist in mesial surfaces of superior biscupids and molars. The occlusion 
is the first consideration, size and depth of cavity are next, although the 
latter is generally regulated by a step as shown in the sketches. This step 



344 



RESTORATION OF TEETH BY CEMENTED INLAYS 



is made of cement or gutta-percha and not of the same extent as if pre- 
paring for a gold inlay (Fig. 365). The gingival borders are more curved 
and the step is rounded and allowance made for greater thickness of 



Fig. 358 



Fig. 359 





porcelain at the occlusal surface. The inlay will be more secure with- 
out a step or interior preparation with any other material, but bicuspid 
and molar cavities are usually too deep for successful matrix formation. 



Fig. 



Fig. 361 





If this can be accomplished, there still remains the difficulty of placing 
the inlay, because of greater bulk than it is possible to get space for; 
however, there can be no set rule, circumstances and good judgment 



RESTORATION OF TEETH BY CEMENTED INLAYS 



345 



must be factors at all times. In any case the cavity must not extend 
into the sulci between cusps unless the sulci are of sufficient size to 



Fig. 362 



Fig. 363 





assure strength of porcelain. Figs. 300, 302, and 304 show enamel 
surface edges without any extension to the sulci. 

Figs. 305, 300, and 307 represent cavity preparation for gold inlays in 
molar and bicuspids, showing the locking or mechanical retention gener- 
ally advocated. By this preparation it is possible to reduce the thickness 
of gold without interference with durability, and the amount of cement 



Fig. 364 



Fig. 365 







required is also reduced to the minimum. Note the square edges and 
angular lines at the gingival border which is not permissible with a 
metal matrix, but wax in proper mouldable state will adjust itself readily 



346 



RESTORATION OF TEETH BY CEMENTED INLAYS 



at these points. A chamfered edge is not incorrect in many instances ; in 
fact, some teachers contend that this is a proper method. It would seem 
that a burnished edge is easier obtained when the cavity edge has a 
bevel; but it is one of those points frequently discussed, and the square 



Fig. 366 



Fig. 367 




edge and bevelled edge preparation have each an equal number of 
adherents. Fig. 366 shows a double compound cavity which is very 
common in bicuspids and molars and not always possible to restore by a 
casting in one piece. To draw the wax without change the axial walls 
must converge slightly toward the occlusal surface and the cavity walls 
having the same tendency toward the outer border. It is not expected 
that the locking or keying system shown in 365 and 367 can be used in 
every case or without variation. Many cases have insufficient crown for 

Fig. 36S 




Roach's suction wax carver. 



this application; in these a post or pins are recommended. Frequently 
there is considerable bulk of wax owing to certain conditions not always 
possible to avoid, which if reproduced in gold will increase the cost of 
the operation very noticeably. The wax can be reduced by melting the 
surface, which will be cemented. Considerable undercut can be made 



FORMATION OF THE MATRIX FOR PORCELAIN 



347 



which will increase retention of the inlay. The best instruments for 
this purpose consist of hollow points with rubber tubes attached. 

The point is heated and applied to the wax, and sucking the tube will 
draw the melted wax into a small section filled with cotton. Electric 
pcints of various forms are also used, and the simpler method is a hot 
amalgam burnisher, wiping the wax from the point after each application. 

The formation of cavities is greatly assisted by special burs and chisels 
of various sizes and curves. 



Fig. 369 




10 


15 


20 


10 


10 


15 


15 


20 


20 


10 


15 


20 


20 


4 


5 


6 


6 


6 


8 


8 


9 


9 


6 


8 


9 


6 


6 


6 


6 


12 


12 


12 


12 


12 


12 


12 


12 


12 


12 








I, 


R 


L 


e 


L 


R 











5 6 7 8 9 10 

Simpson's automatic chisels (proximal). 



12 



13 



FORMATION OF THE MATRIX FOR PORCELAIN 



The difficulties pertaining to the making of a matrix are much reduced 
by having plenty of space between the teeth, and this must be obtained 
prior to the operation by means of tape cotton, or rubber wedges. Me- 
chanical appliances may be used as an assistant when the inlay is made 
and the space for easy insertion is insufficient, but holding the teeth apart 
while making the matrix is usually an interference that can be avoided 
by giving this part of the work proper consideration. Room to work 
is a good rule to follow in any operation, but it is positively necessary 
with the inlay, because the mass is hard and unyielding with breakable 
edges. It must be placed while the cement is soft, and without delay, and 
the slightest interference may mean much loss of time and poor results. 

A gold inlay can be forced to place without damage, but an unpleasant 
experience or two with porcelain will demonstrate the desirability of 
having plenty of space. 

The reproduction of the form of a cavity in foil for an inlay is called 
the matrix in which the porcelain is moulded by heating to a degree 
required to fuse the component parts of the material to a vitrified mass. 



348 



RESTORATION OF TEETH BY CEMENTED INLAYS 



The metal most generally used is pure platinum foil, ttott of an inch 
in thickness. Gold foil No. 40 is also largely used, but only in connec- 
tion with a low fusing porcelain which fuses at a temperature of 300° 
to 500° less than gold. Platinum has the advantage in the fact that it 
cannot be affected by any heat required to fuse the highest grade porce- 
lain. It is not so ductile, or so easily moulded to form, but this dis- 
advantage is counterbalanced by its stability, which allows greater 
freedom from care as to the changing of its form while filling with 
porcelain. 

A gold matrix is invariably invested to prevent its changing form 
and protect it from overheat. This requires time and care, therefore 
platinum is more desirable from many points, and practice will assist 
greatly toward easy manipulation. There has been much discussion in 
the past upon the proper thickness, but it is now generally conceded that 
ToVo °f an inch will suit all cases better than any degree thinner or 
thicker. A thinner material has not the stretching quality, and anything 
heavier will cause a thicker cement line. 



Fig. 370 




A simple cavity on the labial surface of a central will serve to illustrate 
the mode of procedure, which is the cutting of a square section of the 
foil sufficiently large to extend over the adjoining teeth, holding the 
corners in the manner of Fig. 370, and while held securely by the fingers, 
press the foil over the cavity with some material such as spunk, cotton, 
small chamois disks, or a soft rubber point like a pencil end, and in this 
manner the cavity will be outlined on the foil and that portion covering 
the cavity concaved so there can be no mistake as to what portion is to be 
burnished. Then use ball-pointed burnishers of various sizes, such as 
amalgam instruments shown in Figs. 371 to 375, and gently rotate, grad- 
ually pushing the burnished surface to the cavity walls and floor, using 
care not to break the margins. The metal will probably split or break 
as it is forced to place, but unless extremely ruptured, it will not inter- 



FORMATION OF THE MATRIX FOR PORCELAIN 



349 



Fig. 371 



Fig. 372 



11 ■■)» 



mi 



Fig. 37 
® 



fere with final results. When the interior portion is fairly fitted, packed 
with spunk, cotton, or gum camphor, and held securely with a blunt 
instrument, a flat, blunt instrument should be used to get perfect mar- 
gins. Then the packing is removed (ex- 
cept when using camphor, which is burnt 
out), the matrix released with very fine 
pointed pliers, and results noted. 

If satisfactory, the next step is filling 
the mould with porcelain. 

Platinum foil should be thoroughly 
annealed in the furnace muffle ; the heat 
required to improve its softness is at least 
2200° F. The foil purchased at the pres- 
ent time is usually ready for making the 
matrix, having already been thoroughly 
softened at a very high temperature. A 
matrix of complex character will require 
more than usual burnishing, which will 
have a tendency to make the metal harsh. 
It can then be re-annealed to advantage, 
providing the temperature is not less than 
the degree already mentioned. 

An excess of material is recommended 
on labial cavities for the purpose of 
holding securely, but in other places the 
reverse is desired. Notably on proximal 
surfaces, where the excess will interfere 
with removal after taking the form of the 
tooth. Burnishing the matrix in proximal 
cavities, corners, and tips is greatly as- 
sisted by strips of either cotton, rubber 
dam, or goldbeater's skin held securely 
over the metal, insuring its proper posi- 
tion and preventing tearing on the sharp 
cavity edges (Fig. 376). Avoid lapping 
or folding of matrix on cavity edges. 

After the matrix is made the next pro- 
cedure is filling it with porcelain. This is 
done by holding the mould in straight, 
fine-pointed pliers, applying the porcelain 
with a fine sable pencil brush, or the end 
of a spatula made for the purpose (Fig. 
377). The porcelain powder is mixed with pure water, distilled prefer- 
ably, into a stiff paste, and after applying it is shaken to position either 
by tapping or drawing the serrated instrument handle across the pliers. 



350 



RESTORATION OF TEETH BY CEMENTED INLAYS 



This jarring brings the moisture to the surface, and after tracing the 
cavity outline and removing excess with brush, it is laid face down on 
a clean towel, bibulous or blotting paper, which absorbs the excessive 



Fig. 374 




5 6 7 8 

Reeves' set of inlay burnishers. 



moisture. The inlay is then dried out in front of the furnace 
muffle, gradually pushed into the furnace, and fused. Too rapid 
drying will cause porcelain to jump from the mould. A high 
fusing porcelain mixed into a stiff paste will shrink about 
one-fifth its bulk, therefore a second or third fusing is required 
before the inlay can be called finished. If the porcelain is 
thin its proportion of shrinkage will be greater, and it will not 
bridge or carry its weight across any tear or aperture that may 
exist in the bottom of the matrix ; and in deep cavities this con- 
dition is nearly always present, therefore it is necessary to always 
turn the matrix wrong side up and carefully note its condition. 
Clean off any excess with the brush and thus avoid a misfit, for 
it is impossible to remove fused porcelain without distorting 
the matrix or totally destroying the work up to this point. 

The first fusing is usually called " first bake" or "biscuit," 
which is a stage wherein the component parts of porcelain are 
brought together by the heat and made into a hard, homo- 
geneous mass without gloss. 

It is at this stage that shrinkage is most apparent, and it is a 
condition that exists in every porcelain operation of whatever 
dimensions. Shrinkage is governed by quantity and quality of 
material and is a prominent factor toward success or failure. 
In small inlays shrinkage is of less import, but in proportion 
to size it must be dealt with. This shrinkage may be sufficient to dis- 
tort the matrix or cause porcelain to attach to the matrix walls. As 
it is never consistent it is very important to control it, but this is only 



FORMATION OF THE MATRIX FOR PORCELAIN 



351 



possible to a small extent. Shrinkage toward the matrix wall is most 
desired and can be assisted by a slight cut or groove across its greatest 



Fig. 375 




3 4 5 

Sausser's matrix burnishers. 



extent, thereby giving the porcelain an impetus in that 
direction. In large spaces much assistance in controlling 
shrinkage is derived from using small particles of baked 
porcelain mixed with the unfused paste. 

After the first fusing of the inlay the excess platinum or 
matrix material should be trimmed, leaving a working 
margin to allow a refitting in the cavity. In small, simple 
cases this may not be necessary, but in the majority of 
cavities it will assist greatly. If the matrix has become 
slightly altered by shrinkage or careless handling the 
change is noted at once and corrected. In contour work 
it will assist the eye to determine where to add or reduce ; 
in fact, there can be only very small argument against a trial 
of the embryo inlay in its place and reburnishing the cavity 
edges. 

Taking the shade is the first requirement, as the foun- 
dation should approximate the final shade, but after the 
inlay is reburnished this question must be settled in the 
operator's mind, and the final fusing proceeded with. 
First, clean off the inlay with a brush dipped in alcohol or 
warm water, thus removing saliva, blood, or any undesirable 
particles, then carefully fill any crevice caused by shrink- 
age or breakage, finally filling the matrix or building the 
contour or section as desired, always considering shrink- 
age. A second bake may be sufficient, but usually a 
third is required or even a fourth. Frequent firing is not 
harmful providing the porcelain has not been carried to a 
finishing heat previously. Shrinkage must be overcome, 
therefore withdraw the work from the furnace before it is fused and 
note its condition. (See Fusing.) 



352 



RESTORATION OF TEETH BY CEMENTED INLAYS 



After the inlay is properly fired the matrix is removed by turning the 
metal back from the edge with pointed pliers, releasing the inlay. Fre- 



Fig, 376 



Fig. 377 



Fig. 378 




quently small particles of metal ad- 
here to the porcelain. If a pointed 
instrument fails use a discarded bur, 
but in larger inlays small quantities 
of adhering metal will make no dif- 
ference in any way. The inlay is 
•now tried in place, having the cavity 
wet, which helps the porcelain to 

blend with the natural tooth, and at this stage the patient should 
be shown the results, for at a later period the cement and dry- 
ing of the tooth makes a change not always satisfactory, but 
fortunately this is largely corrected by time. 

The inlay is grooved or undercut by wheel disks such as 
hard-rubber, corundum, or copper coated with diamond dust. 
An additional retention is secured by using hydrofluoric acid. 
This acid has a great affinity for all vitrified surfaces, therefore 
great care is necessary that the outer and finished surface is 
thoroughly protected, and the most simple method is to soften 
the surface of a small piece of paraffin or beeswax, and embed 
the inlay face downward. Then cover the exposed surface 
with a few drops of the hydrofluoric acid, and after about five 
minutes wash with a spray of water. 

The use of acid for this purpose is very common, and the 
tendency to carelessness is sometimes checked by a bad burn, 
which is always painful and very slow to heal. After the inlay 
has been subjected to acid it should be soaked in alcohol, which 
will soften the white scale, which is removed by scraping the 
surface with a sharp instrument, and thereby give the cement 
a better attachment to the roughened surface. This is a point 
not generally considered, but it is reasonable and practical, and 
many small inlays have been lost through non-observance of this 
fact. 

As the inlay is now ready for inserting the tooth is dried and protected 
from moisture either by napkins or rubber dam. The latter is preferable, 



LOW FUSING PORCELAIN 353 

but not necessary, providing the operator can use a napkin properly. 
Successful inlays depend upon perfect adaptation and cementation, but 
frequently the operation is spoiled through carelessness or a desire to 
hurry the case to a finish, therefore too much stress cannot be placed 
on this important part of the work. The cement shade should approxi- 
mate the shade of the tooth and inlay, must be mixed thoroughly, and of 
creamy consistency and of medium to slow setting quality. Apply it to 
the cavity with a small spatula tip, then gently press the inlav into posi- 
tion, wipe off excess with spunk or tape, and note the line of demarca- 
tion. If this is satisfactory hold the inlay in position until the cement 
has commenced to harden, then protect from moisture bv covering with 
melted paraffin, wax, sandarac varnish, or chlorapercha. If the inlav 
is extensive it can be ligated with floss silk or held by a wedge, alwavs 
avoiding the use of excessive force, or the delicate porcelain edges will 
shatter. 

A later sitting is required for a final finishing, for the best of inlays will 
need smoothing of edges, which is done with small stones or sandpaper 
disks and strips. 

LOW FUSING PORCELAIN 

Having described the process of making an inlay with the platinum 
matrix and high fusing porcelain, the next consideration will be the 
modifications necessary when low fusing porcelain is melted into a gold 
matrix, therefore the method as described by Dr. J. Leon Williams 1 is 
herein inserted, and is as follows : 

"The thinner the gold can be used the more perfect the fit of the 
finished inlay. A proper set of instruments for shaping the gold form 
and for manipulating the porcelain paste is an important matter. I 
have devised for these purposes the set of instruments shown in Fig. 
379. They are all double-end instruments. Xos. 1, 2, 3, and 4 are de- 
signed for fitting the gold form to the cavity, while Nos. 5 and 6 are 
for manipulating the porcelain paste. The gold should be cut out to 
represent roughly the shape of the orifice of the cavity, but consider- 
ably larger. Fig. 380 shows the proper shape for such a cavity as is 
shown in Fig. 381 at a. It will greatly facilitate the shaping of the gold 
form if a notch be cut out of the gold as shown in Fig. 380, and at the 
same time decrease the chances of breaking through the gold in forcing 
it into the shape of the cavity. It should first be introduced into the 
cavity without annealing. The cut edges will then slide over each other 
as the centre of the gold is forced to the bottom of the cavity. . . . 
Then, with the cotton or spunk tightly packed in the cavity, take instru- 
ment No. 2 and most carefully burnish the gold around the entire edge 

1 Dental Cosmos, November, 1899, vol. xli, p. 1087. 
^3 



354 



RESTORATION OF TEETH BY CEMENTED INLAYS 



of the cavity. This instrument will be found well adapted to reach 
every part of the margin. It will generally be found best to hold the 



Fig. 379 




LOW FUSING PORCELAIN 355 

cotton-wool back a little from the margin of the cavity when one is 
burnishing, with an instrument held in the left hand, and with this 
instrument (preferably a ball burnisher) also press the cotton-wool well 
into the cavity. This holds the gold form well in place and prevents 
rocking while the edges are being burnished. 

"Most operators have found the removal and imbedding of the gold 
to require the most delicate manipulation, and by the methods heretofore 
described one is never quite* certain whether or not this part of the 
operation has been successfully performed until the inlay has been com- 
pleted and tried in place. All of this uncertainty may be avoided by the 
following procedure: Slightly warm and roll up in the fingers a small 
ball or pledget of hard white wax, such as is supplied for crown-work 
and bridge-work. The ball of wax should be just a little larger than is 
necessary to fill the cavity completely; that is to say, it should slightly 
project over the margin of the cavity all around. The wax should be 

Fig. 380 Fig. 381 




Sheet of gold or platinum, notched and ready Right superior central, showing two large 

for adaptation to cavity. proximal cavities to which access is ob- 

tained by cutting freely from the lingual 
walls: a, tooth with cavities prepared; b, por- 
celain inlays for same; c, tooth showing lingual 
surface; d, labial surface after cementing of 
inlays. 

quite stiff when introduced into the gold form as it lies in the cavity of 
the tooth. Now take the broad, thin burnisher, shown in No. 4, Fig. 
379, and press the ball of wax firmly into place. To prevent the burn- 
isher from sticking to the wax, it should first be dipped into French chalk 
or pulverized soapstone. In such cavities as are shown in Fig. 381, 
at a, broad polishing tape, dusted with French chalk, may be used for 
pressing the wax ball into place; but great care should be exercised not 
to pull the tape the least in one direction or the other, as one would do 
in polishing a filling. This would rock the gold form and mar the fit. 
The pull should be steady and equable from both ends of the tape, 
the object being to press the wax everywhere firmly over the edges of the 
cavity. A stream of cold water should now be thrown on the wax, and 
then the wax and gold form should be quickly removed. If this part of 
the operation is done with ordinary care, the finished inlay will always 
be found to fit perfectly. To facilitate the quick removal of the form, care 



356 RESTORATION OF TEETH BY CEMENTED INLAYS 

should be taken to prevent the wax overlapping the gold much at any 
point outside the margin of the cavity. To prevent this and also to 
assist in securing proper embedding of the gold matrix, it is well to let 
the margin of the gold project as much as possible beyond the edges of 
the cavity. 

"The matrix may now be embedded without the slightest fear that 
its shape will be changed. For embedding material I use plaster and 
marble dust. When the investment is sufficiently hard the wax is thor- 
oughly melted out with a stream of boiling water. The investment is 
then dried and brought to a full red heat with the blowpipe. It is then 
allowed to cool, and is ready for packing. Now, the first step in the 
packing of the porcelain paste is the all-important one to prevent the 
porcelain shrinking away from the walls of the matrix. This may always 
be accomplished easily with porcelain of any make if the following 
instructions are carefully observed: Mix the porcelain paste to the con- 
sistence of soft putty, and with the upper point shown in No. 6, Fig. 379, 

Fig. 382 Fig. 383 





a b c 

Showing bicuspid with cavity involving Canine tooth showing at a, large cavity, and 

proximal and grinding surfaces: a, tooth at & and c, large porcelain inlay restoring 

with cavity prepared; b, porcelain inlay; c. contour of tooth, 

inlay cemented in place. 

place a ring of this putty around the entire circumference of the cavity 
leaving the centre quite free or empty. In melting a porcelain paste it 
naturally shrinks toward the largest mass of its own body, or toward 
the centre of the mass. If, then, this centre be removed we should 
naturally expect the mass to shrink toward the circumference, and this 
is precisely what happens when manipulated as directed. The matrix 
always comes out from the first baking with the porcelain everywhere 
firmly melted to the walls of the matrix. Nor will it start from this 
position at any subsequent baking unless it is very much overheated. 
"After each packing of the porcelain paste, a small camePs-hair brush 
with a fine point should be moistened (this is best done by drawing it 
between the lips after the manner of water-color artists) and drawn 
around the margin of the matrix to remove all overhanging particles of 
the paste. If this be not done, the margins of the inlay will often be 
found ragged, and a perfect margin is the most essential feature of a 
porcelain inlay. If gum water be used for mixing the paste, it will be 



CEMENTS AND MANIPULATION 357 

found necessary to remove these overhanging particles with great care, 
as the tendency naturally is for the gum water to cause the particles of 
powdered porcelain to stick to the gold or platinum margin of the 
matrix. In building up the inlay for restoring lost corners of teeth and 
for general contours the work will be much facilitated if, after the first 
baking has been carried through as above described, to secure perfect 
union with the walls of the matrix, a small piece of solid porcelain be 
placed at the point representing the highest point of the contour of the 
inlay. These pieces of porcelain may be made by crushing old porce- 
lain teeth in an iron mortar. Care should be taken to use a piece small 
enough so that the outer edge will not show through when the inlay is 
completed. Corners like the one shown in Fig. 383 may be produced 
in this manner without much difficulty." 

CEMENTS AND MANIPULATION 

What cement do you use? is an ever present query in all porcelain 
discussion, for when there is a failure the cement is generally blamed for 
it. This is a natural deduction when it is considered that a student in 
porcelain is more familiar with cement than with other parts of the 
operation, and if there is a failure it is a natural supposition that it is 
caused by poor material. A cement must be tenacious, finely ground, 
and not quick setting, and of a quality most likely to resist moisture 
when setting, for it is not always possible to keep the work free from 
dampness during that important stage. There are many cements manu- 
factured that have these requirements, and, like other materials with 
similar merits, the choice rests with the operator. They all have the 
same disadvantage, viz., opacity, and the perfect porcelain operation 
cannot be claimed until the attaching medium is transparent, or 
nearly so. The newer silicate cements were thought to have this virtue, 
and many were deceived into using them, but it was found that the 
tenacious period was of short duration and the inlays loosened, causing 
much disappointment. A common trouble is mixing cement too thick, 
thus preventing proper seating of inlay, which makes the joint con- 
spicuous and unfinished. When this occurs quickly remove and cleanse 
every part thoroughly, replacing with a thinner mixed material. 

Shading. — This part of making porcelain inlays is the most difficult 
to the majority, and is an uncertainty with all of us. The problem 
of shrinkage is an unknown quantity, and its remedy is purely mechan- 
ical, but the problem of shading is a combination of various consider- 
ations which may be followed most minutely and then the object may he 
defeated by some detail not always possible to avoid, and this most 
common defect is caused by the opaque cements. The most experi- 
enced have this discouragement, but it can be decreased by using a 
variety of shades and matching carefully. W T e have and can mix an 



358 RESTORATION OF TEETH BY CEMENTED INLAYS 

almost endless variety of porcelain shades, but this is only a part of the 
requirement, for position and tooth density must also be considered, 
together with quantity or size of porcelain to be fused. There is also 
the additional difficulty of correct fusing to reproduce the desired shade. 

Overfusing is the cause of more shade failures than any other, but 
practice will largely obviate this trouble as in other difficulties. The 
most careful directions are inadequate as compared with actual demon- 
strations. When the best has been said, there is still the impossibility 
of reaching all understandings, because this part of the subject appeals 
directly to the artistic sense, and can only be comprehended through 
observation and experience. 

The difficulty of obtaining colors that accurately match the natural 
teeth is a part of inlay work which will always be perplexing, for the 
teeth are largely composed of organic matter, while the material used for 
repair is an inorganic composition, differing in texture and density. When 
selecting the colors for inlays, note the various shades of the natural 
tooth, for frequently there are three or more. If the tooth is vital 
these hues have a distinction which is lost after devitalization, thus 
increasing the difficulties of matching but if the variant and uncertain 
hues of the pulpless tooth are once reproduced in an inlay, the subse- 
quent change attending the cementation is not so marked because of the 
pulpless tooth opacity. 

Position of the inlay is a factor which largely governs the shade, for 
the shadow problem is an incident which forces consideration also. 
This is particularly evident in proximal cavities, and is remedied to some 
extent by making the inlay a shade lighter, and is also controlled by the 
size of the inlay. A lateral incisor being much smaller than a cuspid 
must be treated accordingly, for the density of the latter is much greater 
and will allow a deeper shade. Labial inlays, particularly bordering 
the gingival line, can safely be made a shade deeper; but due con- 
sideration must be given to depth, for if very shallow, the porcelain 
should be of greater density and thus overcome the cement change. 
Inlays of this kind are improved in texture by using nearly all base 
body, and in some instances low fusing porcelain is more effective 
because of its less translucencv. 

With one exception all inlay porcelains are of the same texture 
from base to finish, which is an advantage in the instance just cited, 
but the introduction of a combination consisting of a basal body to be 
covered by enamels was a step toward procuring more natural results 
in the majority of cases. This basal body represents the dentin, which 
in turn is covered by a more transparent material representing the 
enamel, thus enabling the operator to blend the various hues of shade 
of which the natural tooth is composed, thereby producing a trans- 
lucent effect not possible by one dense porcelain no matter how expert 
the operator may be. 



CEMENTS AND MANIPULATION 359 

The restoration of an incfsal tip or corner is an operation that requires 
much practice and artistic skill, for its prominence demands perfect 
shading and adaptation. An operation of this character, while testing 
the ability to shade, has the advantage of not being affected by the 
cement line because of greater proportion or volume of porcelain. 
However, perfection must not be expected because there is always the 
difference between the natural translucency of tooth structure and the 
unavoidable density of porcelain which in certain positions is more 
noticeable by the deflection of light rays. 

A common mistake in shading is in not considering the difference 
between the volume of shade exposed on the porcelain shade guide and 
the quantity required to fill the cavity. 

The mixing of several shades to gain the one desired is largely one of 
intuition, because that shade cannot be known until properly fused. 
This difficulty is unfortunate, but cannot be avoided, as all porcelain 
powders are practically the same, with the exception of a few extreme 
shades, and herein lies the difference between the porcelain artist and 
the painter whose pigments are mixed and the desired shade revealed 
to the eye by simple manipulation. 

Fusing. — It is generally conceded that fusing porcelain is one of the 
greatest difficulties that must be overcome before the novice can feel 
that he has made any advancement toward the successful making of an 
inlay or anything in which porcelain is the component part. It is an 
indisputable fact that this part of the work is a veritable stumbling 
block, and the cause of much discouragement which is only overcome 
by persistent practice, for without this necessary knowledge successful 
results are not possible. 

Porcelain may have a fusing point as low as 1600° F., and varying 
to 2600° F. or even higher, therefore the operator must become familiar 
with these varied heats and their productions. This will mean contin- 
uous applications and training the eye to the various stages and changes 
of the material. Using a timepiece with a pyrometer will be of great 
assistance, but the personal equation is always the dominant factor, and 
herein lies the difficulty of giving directions that will be accurate 
under all conditions. Before the advent of the pyrometer the eye was 
the onlv test of heat, therefore to the beginner this device has consid- 
erable value, together with the fact that the fusing point of the numerous 
porcelains is known. Thus a certain time by the watch with the fusing 
point of the porcelain already known and the pyrometer showing the 
temperature, the fusing of porcelain seems comparatively easy. Various 
sizes of porcelain require different heats, therefore it is absolutely neces- 
sarv to know porcelain in all its changes, without any assistance what- 
ever, otherwise the work will be either over- or underfused, and only by 
chance will it be correct if the machines are depended upon entirely. 
There can be no difference of opinion on this fact, therefore the best 



360 RESTORATION OF" TEETH BY CEMENTED INLAYS 

equipment is the personal knowledge which makes one independent 
of any appliance or set of rules and regulations. It is generally con- 
tended that exposing the eye to such severe changes of light is injurious, 
and this may be true beyond a certain point, viz., 2300° F., a tempera- 
ture sufficient for the majority of our porcelains. There is a product 
by a well-known firm which requires a heat of 2600° F., and there is 
no doubt that the eyes should be protected from the glare of this heat, 
which is unnecessarily high, especially for inlay work. 

As electric furnaces are most commonly used for fusing porcelain, 
it is not very difficult for the student to become familiar with the various 
changes of heat as regulated by the rheostat, and thereby know what 
step will fuse a certain known product. For instance, the first step 
on the majority of furnaces will fuse a low fusing body of 1600° F. in 
probably one minute or even less, but the same heat will fuse a much 
higher porcelain if given longer time. Then, again, voltage must be 
considered, for in many cases it is only approximate, sometimes vary- 
ing three or four points less or that much more, and still coming under 
the class of 110 volts direct. This fact is particularly noticeable in local 
establishments such as office buildings. The alternating current is usually 
more even, and that of 220 however being very strong and harder on the 
furnace muffles. 

The best fusing is obtained by inserting the porcelain at the lowest 
temperature and gradually and slowly raising the heat until the 
fusing point is obtained, thus passing the material through its various 
stages of condensation. These stages are called "biscuiting," and a 
porcelain partially fused may be called a medium or hard biscuit. In 
the latter condition the porcelain has a half glaze and has shrunk to a 
solid mass and is ready for the additional material required to give form. 
Then the porcelain can be fired until it has the finished gloss, which is 
determined by the eye of the manipulator. The best results are always 
obtained by underf using the first bake, because several high heats will 
overfuse the groundwork which reduces its strength and solidity. Using 
a porcelain of slightly lower fusing point the finishing will obviate this 
tendency, which is detrimental to the whole work. 

As an instance of this, note a manufactured tooth which is finished 
in one baking, and the same directions are applicable to carved teeth 
for special cases. A student will readily learn what is a proper glaze 
required if he will take any plain or plate tooth and apply porcelain to 
its surface and watch the various changes until his material has reached 
the same condition. This simple experiment will also help him to 
recognize the heat required for these changes and ultimately enable 
him to acquire self-confidence in the management of the fusing process. 

Porcelain. — Porcelain bodies made for inlay purposes are to be had 
in great variety, both in fusing point and texture; in fact, there is such a 
number for choice that the unexperienced must necessarily be bewildered; 



CEMENTS AND MANIPULATION 361 

however, this difficulty will settle itself like many others that may at 
one time have been just as perplexing. 

For many years there was much controversy regarding the qualities 
of various products, particularly between the advocates of a high heat 
porcelain and those of low fusing qualities. While this question is still 
debatable, it is an indisputable fact that in America porcelains of the 
higher grade have the preference. This may be from the fact that 
the manufacturers of artificial teeth in this country have always used a 
high fusing material, and as the product has stood the test of time it is 
only natural to apply this argument to the inlay question. 

English tooth body fuses about 400° F. lower than the highest fusing 
American body, which places the English on our list as a medium fusing 
material, and its excellent quality is indisputable; in fact, the majority of 
our inlay bodies are really a medium heat, ranging from 2150° F. to 
2300° F., therefore the difference between this fusing degree and that 
of low body of 1600° F. or thereabouts is the point of argument. 

When porcelain inlays were introduced the standard material was 
the continuous gum bodies then well known to porcelain workers and 
put on the market for their use. It was the only material to be had, and 
while it possessed the required quality, it had no variety of shade. 
After some years this was remedied, and the advent of the pyrometer 
enabled us to learn the approximate fusing temperatures of the old 
continuous gum bodies which were found to be about 2300° F. These 
bodies have not been much improved upon either in quality or finish. 
The first low fusing material was introduced in 1892 by Dr. Downie, 
but was not satisfactory for inlay work because of its poor shades, 
although it was quite extensively used for crowns. A few years later 
Ash & Sons made up a small assortment much improved in shades. 
Dr. Jenkins introduced his low fusing enamel in 1898. After this 
date manufacturers of porcelain produced an assortment suitable to 
all circumstances. 

The wearing qualities of various porcelains are practically equal in 
certain positions, notably in cavities not extending to incisal edges or 
masticating surfaces, and in shallow labial cavities. Low fusing porcelain 
has an advantage from the fact that its opacity prevents the cement 
from changing the shade, which is frequently the case with a high 
fusing and more translucent body. 

Workers of higher fusing porcelain will be more or less conversant 
with all porcelains and their variations, because this field is greater 
and has practically no limitation; but a low fusing porcelain worker is 
usually at sea if not using that material, while anyone accustomed to 
the higher heats can fuse the lower, providing care is used not to 
overheat. Too much heat is fatal to low fusing body, as it means not 
only loss of shade, but also loss of strength. The same rule applies to 
all porcelains, but not to the same extent if the porcelain is high fusing, 



362 RESTORATION OF TEETH RY CEMENTED INLAYS 

for its working latitude is much greater. Low fusing material is usually 
moulded in a gold matrix which is invested. Platinum must be used 
as the matrix for higher heat porcelains, and no investment of it is 
necessary. 

As pyrometers are commonly used, a few of the most popular bodies, 
and approximate fusing points will assist the student, bearing in mind 
that these figures are based on two-minute tests, with conditions favor- 
able for accuracy. 

Low fusing. Medium fusing. 

Ash & Sons, 1550° F. Brewster's Enamel, 2080° F. 

Jenkins, 1550° F. S. S. White's Medium, 2100° F. 

Downie's, 1550° F. Ash & Sons' " High," 1900° F. 
Brewster's Gold Matrix, 1800° F. 

High fusing. 

S. S. White's Inlay, 2300° F. 
Close's Continuous Gum, 2300° F. 
Whiteley's Inlay, 2200° F. 
Whiteley's Inlay special, 2400° F. 
Brewster's Foundation, 2200° F. 
Consolidated Inlay, 2600° F. 
Johnson & Lund's, 2500° F. 

Furnaces. — The advancement in the matter of furnaces has been so 
rapid that less than thirty years ago the user of porcelain depended 
on such an apparently crude appliance as is shown in Fig. 384 (old 
coke furnace), and yet the beautiful porcelain dentures and carved 
work of the older dentists has not been surpassed. 

It was early recognized that a small, quick heating appliance was a 
necessity, and this difficulty was solved by Dr. C. H. Land by inventing 
the first gas furnace in 1886. This machine, while a great improvement, 
was slow and tiresome, as the constant use of bellows was necessary for 
half an hour before the furnace was hot enough for use. A smaller 
and quicker gas furnace succeeded this, more applicable for inlays and 
crowns, and was successfully used until superseded by electrical outfits, 
which have the advantage of cleanliness, purity, and noiselessness. 

A gas furnace is noisy and gives much trouble in carbonizing the 
porcelain, or as it is usually termed "gassing." Fortunately, that is a 
discouragement of the past, for electricity has reduced fusing cares to 
the minimum. Other furnaces of that time were the Parker-Stoddard, 
Downie, and Fletcher. 

Dr. L. E. Custer invented the first electric furnace in 1894, and while 
it was a distinct improvement, there was much trouble in muffle wires 
burning out, which caused much delay and retarded the general use of 
this class of furnace. The Custer electric furnace as now perfected 
is practically useful, and is a strong favorite. Five years later the Ham- 
mond (Fig. 385) was patented, and immediately became popular from 
the fact that a "damaged" muffle could be replaced immediately. 



CEMENTS AND MANIPULATION 



363 



This furnace has remained a favorite until the present time, but is 
being gradually replaced by the S. S. White Co.'s new furnace (Fig. 386), 



Fig. 384 



Fig. 385 





Old style coke furnace. 



The Hammond furnace No. 1 , 



Fig. 386 




S. S. White furnace with pyrometer attachment. 



364 



RESTORATION OF TEETH BY CEMENTED INLAYS 



which is similar, but improved in certain details, and it is also arranged 
with pyrometer attachment. 

In 1902 the Pel ton appeared. Besides these furnaces there are sev- 
eral others distinct in form, and all, with few exceptions, have a pyrom- 
eter attachment. They are : the Fletcher, Peck, Gerhard t, and Roach, 
and others including the Price, which has been withdrawn, although 
Dr. Price was the first to apply the pyrometer. 

In addition, furnaces are slso made for gasoline use. The principal 
types are the Turner and Brophy. They are of great value to the out-of- 
town dentist, because they not only fuse porcelain, but have equal facility 
in blowpipe work and metal heating, thus enabling those not posses- 
sing gas or electricity to be practically on the same footing with the city 
practitioner. 

GOLD INLAYS 

Gold Matrix Inlays.— Gold matrix inlays have been used to advantage 
for many years, but the casting process has largely supplanted this pro- 
cess, therefore a description of these difficult and extensive operations 
must be considered unnecessary in this day of later improvements. It 
is an erroneous idea, largely prevalent in the profession, that matrix 



Fig. 387 



Fig. 388 



Fig. 389 






Cavities and restoratives suitable for and illustrating the gold matrix inlay method. 



gold inlays are entirely out of date, for there is no doubt of this work 
still having its place and that it is applicable and successful under 
certain circumstances. Its chief recommendation is the saving of much 
valuable time. One predominant reason why the matrix inlay does not 
appeal to the general dentist is that phase of the operation which is the 
first consideration, viz., the making of a matrix. Having that knowledge, 



CEMENTS AND MANIPULATION 



365 



the rest of the operation is so simple that very little practice will accom- 
plish most satisfactory results. 



Fig. 390 



Fig. 391 



Fig. 392 






The process of making gold inlays is recommended for use in various 
positions where much contouring is not required, such as proximal 
cavities in bicuspids and molars, extending slightly between cusps. 



Fig. 393 



Fig. 394 



Fig. 395 






Cavities and restoratives suitable for and illustrating the gold matrix inlay method. 



Occlusal surfaces between cusps, shown in Fig. 387, buccal cavities on 
same teeth (Figs. 388, 389, and 390); and small corners and incisal tips 
on anterior teeth which preclude the use of porcelain (Figs. 391 to 395). 



366 



RESTORATION OF TEETH BY CEMENTED INLAYS 



Fig. 396 



In these latter positions the proof of the advantage of this work is the 
fact of the success of the method when every other material had been 
tried and failed after short use. An expert gold operator may not treat 
this assertion seriously, believing that a hammered gold filling will be 
equally successful. 

In many cases, particularly in hard structured teeth, this is quite 
possible, but in frail teeth the application of this kind of inlay is simple, 
safe, and satisfactory, and saves time. 

The procedure for this work is to make a matrix of the cavities as for 
porcelain, either in platinum of the same gauge or gold of No. 30 foil, 
with the difference that as the matrix will remain part of the filling, it is 
not necessary to burnish or stretch the foil to position. It may be 
carried to the bottom and walls with no attention to folds or creases, but 
the edges must be well defined, as in porcelain work. When the matrix 
is made and while still in the cavity, matt or sponge gold of any descrip- 
tion is loosely packed into it and in sufficient quantity to support the 
walls and cover the floor and the break in the matrix which is then 
removed and two or three small pieces of 22 k solder applied to the 
soft gold and melted with the blowpipe (Fig. 396). The solder will run 
into the gold to the matrix walls, thus making the 
whole piece rigid. The excess matrix may be re- 
moved if so desired and replaced in the cavity and 
thoroughly burnished; it is again removed and with 
a fine pencil brush liquid rouge is traced over the 
whole outer surface to the cavity margin. This 
must be carefully done, for the slightest irregularity 
of the outline will be reproduced by the gold. The 
tracing of the liquid rouge prevents the gold from 
flowing beyond the margins, therefore it is a good rule to coat the 
underside, particularly if the matrix is of gold foil. Small pieces of 
solder, or pure gold if so desired, are then dropped in connection with 
the cavity and melted with the blowpipe. After the desired form is 
secured the excess matrix is cut away and the inlay is ready for 
treatment, as already described into casting process. 

Rowan's decimal gold No. 30 for packing the matrix has an advan- 
tage over matt gold because it is composed of a thin layer of platinum 
between two layers of gold, therefore it is only necessary to throw the 
flame on this combination while it is in the matrix and the gold portion 
immediately acts as a solder which unites the whole without any addi- 
tional solder. This combination should be used only with a platinum 
matrix, and in any case the rouge should not be applied until after a 
trial fitting, because the burnishing will carry the tracing from the edges 
to the interior and prevent the solder flowing easily. 

Cleanliness and care will obviate much trouble, for gold will not 
flow where there is the slightest deposit of rouge. Small tips and cor- 




CEMENTS AND MANIPULATION 367 

ners are contoured by the use of small pieces of gold plate cut to 
desired shape or melted into small globules, which extends the contour ; 
these are afterward ground to shape. A little practice will insure very 
satisfactory results. 

The Cast Gold Inlay.— There have been many inventions in dentistry, 
but it is doubtful if any improvement was ever received with greater 
enthusiasm than that of the inlay casting method. 

Dr. Wm. H. Taggart, of Chicago, has the distinct honor of being 
the inventor of the first appliance for this purpose, having demon- 
strated its possibilities before a meeting of the First District of New 
York, in January, 1907. 

For twenty years the profession had been gradually accepting the 
inlay in its various forms, also the fact that a cemented filling had merits 
worthy of consideration, therefore this newer and more perfect process 
was received without reservation, with the result that almost every den- 
tist is a practitioner of this method. The almost unlimited possibilities 
of the casting process has developed newer operations almost too numer- 
ous to mention, including inlays of all forms, crowns, and various bases 
for such work, cast bridges, partial and full plates, dental splints, and 
various appliances. In fact, the ingenious dentist has by no means 
exhausted its possibilities of practical application. 

The machines for performing this work have rapidly multiplied in 
design, and they are made in such variety of form and cost that no one 
need be dissatisfied. 

Casting molten gold in various forms can be done in a myriad of ways, 
but the basal technique is the same in all instances, therefore the de- 
scription as given by Dr. Taggart is necessarily authoritative, and is as 
follows : l 

"In all my casting work, whether operative or prosthetic, I am using 
a special wax known as 'Taggart 's Green 'Wax.' This wax has been 
made green in color because it will thus be easy to differentiate between 
the wax, the enamel, and the gum tissue when working directly in the 
cavity; and while most excellent results may be obtained by taking 
impressions and making amalgam or cement replica models of cavities, 
manifestly no duplicate of the cavity, and no articulated model thereof, 
can be so accurate as the cavity itself and the patient's jaws, which must 
give the exact occlusion. A little practice will convince the majority 
that it is better to work within the mouth when making inlays. 

"This wax is warmed in water not above 138° F. until it is thoroughly 
softened throughout the mass. It must not be warmed with dry heat, 
nor manipulated with the fingers, with the idea that the softening can 
be hastened in that way. A piece the size of the stick and of length in 
proportion to the size of the cavity should be softened and carried in its 

1 Items of Interest, April, 1908. 



368 



RESTORATION OF TEETH BY CEMENTED INLAYS 



original form to the cavity, and firmly pressed into the cavity with the 
fingers, allowing the excess to act as a piston in forcing it into all parts 
of the cavity. The patient should then close the jaw, biting firmly into 
the wax, giving the imprint of the opposing cusps. Then have him 
move the jaws, as in the act of chewing gum; this wears down all the 
high points and gives the correct occlusal form. All excess wax is 
trimmed away and the wax carved into the exact form desired for the 
completed inlay. A special quality of the wax is that it can be beauti- 




fully carved, remaining hard enough for this purpose even at the temper- 
ature of the mouth; and as the process exactly reproduces every form 
and line of the wax model, and as wax is more easily carved than gold, 
it will repay the operator to spend a little time, care, and artistic skill 
in making the wax model. The wax inlay remains hard enough in the 
mouth so that it may be lifted from the cavity without change of form, 
and it can then either be held in the fingers for further carving, or 
artistic touches may be added when the wax inlay is mounted on the 
sprue, as in Fig. 398. 



CEMENTS AND MANIPULATION 



369 



"When finished the wax inlay is held in the left hand and the sprue 
wire in the right. Then heating the sprue wire until it will melt its way 
into the wax, the two are brought together, as shown in Fig. 399. 



Fig. 398 



Fig. 399 





"The inlay and sprue wire are then placed in the crucible former, as 
in Fig. 398. The investment is properly mixed in the following manner: 

"The large cup on the measuring device (Fig. 400) is to be filled lightly 
with investment and scraped off flush with a straight-edged, silver- 
plated dinner knife, which can be used as a spatula. 



Fig. 400 




"The small end of the measuring device (Fig. 400) is filled even 
full with water and the two mixed together. For the large flasks just 
double these quantities. Then place the rubber plaster bowl in the 
position shown in Fig. 401, and jar it on the bench, rotating it slowly 



Fig. 401 




in order to smear the whole inside of the bowl with a thin layer of 
investment. This allows all air easily to work out through this thin 
layer. Carefully place the investment on the inlay in such a way as 
24 



370 



RESTORATION OF TEETH BY CEMENTED INLAYS 



absolutely to avoid all air bubbles being caught in the investment, 
because these air spaces would be filled with gold in the casting. 

"This stage is represented by Fig. 402. Apply the flask, round 
edge down, and pour the investment until the ring is full. Do not jar 
the investment to make it go to place; this only causes the contained 
air in the investment to form large bubbles against the wax. Rotate 
the flask slightly and cover, and the mass will settle; then, if necessary, 
add more investment and turn the flask over on to some smooth surface 
and press the excess to place, allowing the excess to squeeze out of the 
small hole in the flask. The investment should be allowed to set for at 
least fifteen minutes, or it can be set aside for an indefinite period; but 
better results are obtained by drying out as soon as the plaster has set. 
When ready for casting, the crucible former is removed, as in Fig. 403, 
the flask is set over the Bunsen flame, and at first slowly dried out; as 
soon as the steam ceases forming a higher heat can be turned on and the 
wax burned thoroughly. 



Fig. 402 



Fig. 403 





" It is now ready for the casting machine, and a generous button of 
24 k gold, at least five pennyweights, should be placed in the crucible. 
As there is no waste in casting, it is always best to have plenty of gold 
in the crucible. 

"Referring to Fig. 397, the machine is operated in the following 
manner : 

" The flask 9 is placed in ring 10. The city gas is connected by hose to 
12. The nitrous oxid blowpipe 8 is turned at right angles to the machine 
and the city gas lighted, making a smoky flame about four inches long. 
The handle to the reducing valve 3 is turned backward, or to the left; now 
open, with the wheel, the main nitrous oxid cylinder valve 1. This 
allows the high pressure of the nitrous oxid gas, which in a full cylinder 
is one thousand pounds, to pass into the reducing valve 3, and by 
turning the bar handle of the reducing valve 3 to the right, any degree 
of pressure can be indicated on the gauge, although five to eight pounds 
is sufficient. The needle valve 21 is opened to allow nitrous oxid to 
flow through 11 to unite with the city gas, which comes in at 12. By 



CEMENTS AND MANIPULATION 371 

mixing the proper proportion of nitrous oxid with the city gas a blue 
flame is made about three-quarters of an inch long. Now place the flask 
9 in the machine ring 10, using the tongs; then turn the blowpipe to the 
proper position to play on the button of gold, and when the gold is in 
a boiling state, bring the handle forward with a decided jerk, which will 
automatically throw the blowpipe 8 out of the way, and automatically 
bring the pressure plate 7 down airtight on the flask 9, and automatically 
hold the lever down by closing the lock 5, and automatically start the 
alarm whistle 4, which is regulated as to its volume of sound by the 
small needle valve 20. The object of this alarm is to draw attention 
to the fact that the main valve on the nitrous oxid cylinder 1 is to be 
shut off when the casting is finished, or the nitrous oxid will escape 
over night. The sustained pressure should be kept on top of the gold 
for thirty seconds, after which the flask can be taken out and put into 
water, when the investment can be washed off. The inlay should now 
be placed in 50 per cent, hot hydrochloric or full strength hydrofluoric 
acid, to make certain that all foreign investment is dissolved off. 

"The excess gold is sawed off at the sprue and the filling mostly 
finished out of the mouth. It is always best to examine the cavity side 
of the inlay under a magnifying glass so as to see that there are no little 
beads of gold, which would prevent it going thoroughly to its seat. As 
these fillings fit the cavity so tightly, it is best to drive them to place 
several times with a stick and mallet before setting, and when the cement 
is in place, seat again with mallet and stick. 

"This repeated tapping with the mallet in different directions will 
seat an inlay better than it can possibly be done by direct pressure on the 
inlay. The margins can now be gone over with stones and disks of 
polishing tapes and finally polished. When prosthetic pieces are being 
made, Taggart's green wax should be kept at a workable temperature 
by frequently holding the model and wax in water at 138° F. 

"The possibilities for displaying ingenuity in constructing different 
prosthetic pieces are only limited by the versatility of the dentist. 

"The nitrous oxid blowpipe for this work has decided advantages 
over any other blowpipe flame, for the reason that the gold can be 
melted so much more readily, and brought into a more fluid condition 
and shot into the mould while the mould is practically cold, and not unduly 
expanded, as the investment would be if the gold were melted by the 
ordinary blowpipe." 

In a further communication Dr. Taggart states: 1 

"Wax and its Treatment. — To be scientifically correct, a wax must be 
of such a nature as to be sluggish in movement, and which, at the tem- 
perature of the mouth, will absolutely break before it will bend. With- 
out this quality there is no certainty that it has not become distorted, 
especially in complicated cavities. 

1 Items of Interest, July, 1911. 



372 RESTORATION OF TEETH BY CEMENTED INLAYS 

"With soft waxes and the use of cold water it is possible to obtain 
fairly good results in ordinary cavities, but where there are any com- 
plications, such as are found in M. O. D. (mesial-occlusal-distal) cavities, 
the wax, as soon as the cold water is withdrawn, almost immediately 
resumes the temperature of the mouth, and while it may be easily 
withdrawn from the cavity, there is no telling to what extent it may 
have been bent, and this condition will not give a high percentage of 
successes in the places which should be the most accurately filled. 

" I have made eleven hundred and fifty different mixtures of waxes 
and gums and did not succeed in having continuously successful results 
until a wax was obtained which possessed the foregoing properties, but 
others seemed to think it required too much effort to get it to a workable 
condition. From the start it was found that the uniform plasticity 
throughout the whole mass could best be obtained by warming in hot 
water, but in trying to do this in a hurry the surface was made softer 
than the internal mass; yet if sufficient time were used to allow the 
whole mass to be thoroughly heated throughout, excellent results were 
obtained. To surmount the problem of heating the wax properly, I have 
devised an automatic electric heater (Fig. 404). When the instrument 
is set to work so as to give the proper degree of plasticity, it will always 
duplicate this temperature, but it must be allowed time to arrive at 
this correct temperature, and by making it automatic this can be accom- 
plished to a nicety. As soon as I commence to prepare the cavity, the 
heater is started, and this gives ample time for the wax to be thoroughly 
warmed throughout its mass, so that when the cavity is finished the 
wax is ready to be used, without loss of time, with annoying conditions 
removed, and with continuously duplicated and gratifying results. This 
instrument has brought the moulding of the wax pattern down to 
practically a scientific basis. 

"This instrument (Fig. 404) has as a heating element a 16-candle-power 
lamp, with a carbon filament. The carbon filament is being abandoned 
for lighting purposes, because it furnishes more heat than light. The 
Tungsten filament furnishes more light than it does heat. For that 
reason I have used the carbon filament to furnish the heat. 

"It works on the following principle: There is a glass disk, which 
can be turned to one side in order to place the wax on it. As all the 
heat comes from one direction, a flat metal disk or surface would receive 
heat upon its upper surface, and the under surface of the wax would be 
cool. I found that one of these disk glasses is thin enough so that as 
the heat strikes it, it is reflected back so that the under side of the wax 
is warmed as well as the upper. I have had wax in the instrument 
for fifty-six hours at a time, and when I examined it it was plastic in 
its mass, and no more heated on the upper than on the lower side. 

"The electric heating apparatus was hard to control automatically 
if the current were allowed to go in a continuous path, but by adopting 



CEMENTS AND MANIPULATION 373 

the principle I have used, of having the heat all on or all off, it permits 
the intermittent heating of a thermostat. It heats the thermostat, 
which, as soon as it gets a little too warm, breaks the electric circuit. 
When the electric circuit is broken the thermostat begins to cool down, 
and the thermostat throws the current into the lamp again. It works 
by excessive heat, and it shows there is not a one-hundredth degree of 

Fig. 404 




difference in temperature between the surface on one side or the other. 
Sometimes it will flash 50 or 60 times in a minute; sometimes slower. 
The reason is, it is a very sensitive test of the voltage that is passing 
through the wire. It has been often noticed that when the lights would 
go up high it would make the room light enough. When the current 
is at a high voltage the lamp is heated more, and that works the 



374 RESTORATION OF TEETH BY CEMENTED INLAYS 

thermostat quicker, and as soon as it is worked quicker, it immediately 
drops down. The movement is caused by that voltage. 

"The wax is placed on the glass disk and the even temperature 
throughout the whole mass has a great deal more to do with the correct 
moulding of wax in a tooth cavity than appears. It is peculiar, but a 
soft, wobbly condition of the surface of the wax will invariably make it 
shrink from the cavity walls ; whereas, if the wax is of a uniform texture, 
it will move to its place in an exact way, and there will be no change in 
form when it cools off. 

" Investments for Cast Inlays. — This problem of investments seems to 
have caused more trouble than even the wax problem did, and justly so, 
as after the pattern, which must be accurate, the mould must be scien- 
tifically correct. A great many of the faulty adaptations, aside from 
those caused by distorted patterns, come from improper investments, 
or good investments improperly handled. 

"One writer has given several pages of meaningless statistics about 
investments. I have not been able to fathom their meaning, because, 
if investments are tested under conditions which should never be 
allowed, no number of pages of statistics can make me believe that this 
would be a scientific treatment of the subject. For instance, temper- 
atures of 1000° are mentioned; as a matter of fact, such a temper- 
ature is so far beyond the requirements that the article loses weight 
as a scientific treatise. The temperature required in order to do 
scientific casting should never be higher than just enough to burn out 
the wax. Anything beyond this is absolutely harmful and brings the 
investment to a temperature where the ingredients themselves are burned 
and give off gases which are very objectionable in a mould. 

"The temperature in the flask at which casting should be done has 
not been" thoroughly understood. A hot flask is an expanded flask, and 
an expanded flask means an expanded hole inside, and an expanded hole 
means a misfit casting. 

" I think one of the most scientific reasons why I have such continu- 
ously satisfactory accuracy in the fits of my cavities lies in the fact that I 
never cast in a mould hotter than the temperature of the room. In 
other words, always allow the flask to become cold. This gives two con- 
ditions, both important. One is, the mould is not distorted, and the 
other is, that the metal flask, in being allowed to come back to a normal 
temperature, hugs the investment tighter and gives it a support which 
is very helpful in resisting the pressure from within. 

"Most of the handling of investments is done in a very unscientific 
way; as a rule, there are no two times that the conditions are made the 
same. Experiments in sufficient number should be made to determine 
the correct quantities of water and powder, and then these proportions 
should invariably be duplicated; otherwise, how can uniform results be 
obtained? There must be some proportion of water and powder in any 



CEMENTS AND MANIPULATION 375 

investment, good or bad, which is the correct one for best results with 
that particular investment, and when this is determined it should 
invariably be duplicated. This can only be done by weighing the 
ingredients and not by measuring, as it is impossible to always get the 
same quantity of powder in a vessel unless it is weighed. A little pressure 
or tapping will alter the quantity away beyond reason. From the start 
I have insisted on exact weighing of both water and powder, and this 
accounts again for a high percentage of uniform results in my work. A 
rule of thumb method will never accomplish scientific casting. A little 
water and a little powder, and if too thick, a little more water; and if 
this time it is too thin, then a little more powder, will never give two 
mixtures alike, and if the consistency of mould is not twice alike, the 
casting results certainly cannot be duplicated. 

"A good investment should be so compounded as to make it possible 
to pour it into the flask, and have plenty of time to know that the wax 
is thoroughly surrounded. A thin investment also allows the contained 
air to more easily escape. When I was using a thick investment and 
manipulating it hurriedly, as was necessary, I would find pimples on the 
gold far in excess of what I thought was caused by the contained air 
in the plaster ingredient, and I came to the conclusion that gases must 
be evolved after the investment was in its place in the flask. By making 
a proper mixture of ingredients, it now allows me so to manipulate the 
material that any contained air or gases are allowed to escape before 
the flask is filled. 

"In order easily to weigh and mix investments to get uniform 
results, I have devised several instruments by means of which this 
object can be obtained and scientific casting has taken a long step 
forward. 

"Investment Mixer. — This apparatus was among my first instruments 
for mixing investments. It is an open tube, and a movable other end 
to the lever. In the centre is the fulcrum. There is a movable weight. 
Imagine the fulcrum at a certain point. On top of it I have a spirit level. 
Without that it would be impossible to tell with the eye whether this 
end or that end was too low. If either condition existed correct pro- 
portions of water and powder could not be obtained. As soon as the 
spirit level comes to a centre, that is the correct amount. 

"This is a movable weight between two nuts. When it is to the 
left there is a certain amount of powder, and when to the right there is a 
certain amount of liquid. 

"The spirit level shows the weighing beam is level. I now move 
the weight over to the right side. That brings it out of balance. By 
squirting the water in, and bringing it back to balance, we have the 
correct quantity of water. 

"Those two ingredients are in there in the proper proportions, and 
those conditions can be duplicated every time, and after the proper 



376 RESTORATION OF TEETH BY CEMENTED INLAYS 

proportions have been found, the advantage can be seen. It is liquid 
enough to shake it and get the ingredients properly mixed. 

"The element of time comes in. These gases seem to be evolved 
from the chemical action of the water on the plaster, hence the liberation 
of contained air and gases. The plaster taking up the water, whatevei 
gases or contained air there may be in the powder or water, are given a 
chance to be eliminated by rolling it from one end of the tube to the 
other, and giving it a slight tap occasionally. As it is rolled in this way 
the gases come to the surface. They have a great attraction for the 
water, but a little tap or jar will break them loose, and then the process 
is repeated and the rotary motion given. Three or four minutes of time 
can be consumed in this way, and the investment is still in a workable 
condition. 

"When it is ready, the inlay which is on the crucible former is care- 
fully painted over with a small earner s-hair brush, so that there is no air 
pocket concealed in any angle, and the investment is then poured into 
the flask. It is in a liquid condition, and is absolutely free from all the 
gases and bubbles that have formerly caused annoyance, and which 
invariably produced the little nodules of gold on the surface of a filling. 
It is easily seen how a thick investment could confine this air, and the 
air, having some buoyancy, will rise somewhat; but it has not enough 
buoyancy to come out, especially when it strikes the under side of the 
inlay. Any jarring of the flask at this time is the worst thing that can 
be done, because the colonies of small bubbles of air and gases congre- 
gate and cling to the under side of the wax pattern. The investment 
stays thin for ten or eleven minutes, and apparently it is so liquid it 
never will set; but when it is looked at again after turning aside for 
a moment and forgetting it, it has set. It turns rapidly from a liquid 
to a solid. At the end of twenty minutes it is ready, even when mixed 
in this liquid form, to place on the fire. 

"In order to mix these ingredients properly I felt as though the 
instrument was rather crude, and that a more accurate and automatic 
instrument should be made (Fig. 405). 

"In this vessel I mix the ingredients. There is a spring that allows the 
rod to be shortened. It was put in a little hole in one side, and one on 
the other side. In the other device there was a chance to change the 
length of the lever in the scale beam. In other words, in dropping the 
powder into it the bulk of it would pile up on one side. That would 
make the beam longer, and a true measurement would not be obtained. 
If it were possible always to place it absolutely in the centre it would 
weigh properly. The liquid takes care of itself. I made a movable 
joint in this, so when the powder is put in, it tips it over and brings the 
centre of gravity below the point of support. 

"The instrument is handled as follows: I hang it on the fulcrum. 
The arm has a spirit level in the top, the same as the other. The weight 



CEMENTS AND MANIPULATION 



377 



is pushed to one side, the powder is placed carefully; it must be remem- 
bered that a little too much powder or too much water will make it of 
such a consistency that it will not roll in the container, but will become 
sluggish and mushy. The weight is now moved to the other side of the 
scale beam. Water is poured in until it comes to a balance again. The 
spring is removed and the lid placed on and shaken up so as to get the 
ingredients mixed. It will be noticed that the arm leading off from it is 
placed at an angle. This is placed on the motor, and we have a cog 
motion here which reduces the speed of the container to about sixty 



Fig. 405 




revolutions a minute. This mechanism is an automatic one. In my 
work I allow five minutes for the mixing. Five minutes is better than 
three minutes, because every chance is given the gases to escape in this 
time, and the five minutes may be occupied with other work. I take 
the wax inlay after it has been placed on the sprue wire, start the 
automatic instrument, and then do the artistic carving and finish up 
the wax filling; and often I have plenty of time to do all the carving that 
is necessary while this mixing of investment is going on. By setting the 
clock at five minutes the mechanism revolves. There is a little jerking 



378 



RESTORATION OF TEETH BY CEMENTED INLAYS 



motion each time. This jar is to burst the air or gas bubbles. The bell 
rings and the machine stops automatically. The automatic device for 
stopping is nothing more than a snap switch placed on the alarm end 
of the clock, so that the alarm movement is the one that throws off 
the switch. 

"The material is now ready to be poured into the flask. It is of a 
much better consistency even in the few minutes I have mixed it — freer 
from air bubbles — than in any other way in which I can mix it. If it is 
jarred in a more violent manner more air is apt to be pumped into it. 

"By allowing the disk to revolve alone the angle at which the con- 
tainer is set is continually changing, which keeps the liquid investment 
constantly changing its place and spreads it in a thin layer on the inside, 
and the jar bursts the gas bubble. 



Fig. 406 




" There is another automatic mixer (Fig. 406) that can be connected 
with any of the lathe motors. This is a Ritter. This machine works on 
the same principle as the other. As the mixing goes on for the 
requisite number of minutes the clock movement goes along, and the 
jarring motion is obtained. The fact that there is an alarm loud enough 
to draw attention to the fact that the work is ready, is better than the 
assistance of anyone in the mixing. It permits the work to be done 
identically every time. 

"Method of Removing Wax from Mould. — The case is now flasked. It 
is seldom that wax has been burned out successfully twice alike. As 
this process takes considerable time and it is not considered necessary 
to watch it, there is great likelihood of overheating and spoiling the 
mould by forgetting it, sometimes leaving it on the flame for hours. If 
continuously duplicating conditions, as I have previously outlined, is 



CEMENTS AND MANIPULATION 



379 



of any importance in scientific casting, it is equally so in the simple 
burning of the wax. I have devised a burner for this purpose which 
does the work automatically and thus becomes a great time saver. 

" Automatic Apparatus for Burning Out the Wax. — In this instrument 
(Fig. 407) I have three different degrees of flame. If great care is taken 
when the first low heat is put on, and plenty of time allowed for the 
water to be evaporated out of the investment, as much heat as is 
desired may afterward be put on and as fast as may be wished. 



Fig. 407 




"This low heat is without signification unless it is confined. The 
swaying of the flame by draughts would mean continual variations of 
temperature. I put a tube over as a chimney to make the flame come 
to the top always and to prevent its swaying. 

'On the back part of another alarm clock there is a disk which has 
three steps and a valve of special construction. This level first rests on 
the first step, and as it is set for five minutes the clock moves at that low 
heat, and then drops on to the step next higher. That temperature is 
kept up for another five minutes, which precludes the possibility of any 
further moisture which might suddenly burst and destroy the invest- 



380 RESTORATION OF TEETH BY CEMENTED INLAYS 

ment. As time goes on — another five minutes — it drops off, and it goes 
up another step. That, we will say, is the third and highest temperature. 
At the end of that time another five minutes elapse, and the switch goes 
off and the flame goes out. 

" Gold for Casting. — The next phase of scientific casting concerns the 
gold itself. If there is any one thing more than another which has 
hindered the scientific casting of inlays, it has been the eagerness of 
the dentist to use all of the old refuse gold about the office. The question 
of saving on an average sized filling, say as large as one and a half penny- 
weights, would amount to ten cents w^hen pure gold scrap is used. In 
the case of 22 k scrap, fourteen cents would be saved on the filling, and 
in 20 k scrap, about sixteen cents. For a filling of this size not less than 
ten dollars should be obtained, and not more than a hundred. Now 
let us see how this figures as to cost. If a failure occurs on account 
of using bad gold on a 22 k scrap filling at ten dollars each, it would 
require seventy-one and three-sevenths fillings, and on the one hundred 
dollar filling, seven hundred and fourteen and two-sevenths fillings 
to come out even on that one failure. Real, ethical, scientific, artistic, 
humanitarian, and opposed-to-patents dentists cannot afford to pros- 
titute themselves to this extent. 

"So much for the commercial side. Now, as to the scientific aspect 
of knowledge gained and verified by exact observation and correct 
thinking. 

"Dental golds are alloyed with either silver or copper, and in case 
of solders, zinc is used. It is a well-known fact that silver and copper, 
or any baser metals, readily absorb gases when melted, and these gases, 
principally oxygen, form oxids of the metal, and on cooling evolve these 
gases, which causes the blowholes, or porous cast. The elimination 
of these absorbed gases also causes the sputtering in alloyed gold, 
which does not occur when pure gold is used, as the latter in its 
melted state does not absorb gases; consequently, when cooled from 
the melted condition, it has no gases to squeeze out, and it is necessarily 
exceedingly homogeneous. 

"While it is known that platinum is non-oxidizable, and might 
have properties helpful to gold, it must be borne in mind that platinum 
at these high temperatures has a very great affinity for silicon, and a 
piece of pure platinum melted in a crucible with but a small portion 
of silica will become very brittle. This possibly accounts for the brittle- 
ness of clasp gold when cast, as clasp gold is supposed to be alloyed with 
platinum. 

" All of these conditions I have found out by practical experience, and 
have had them verified by expert metallurgists. What do these experi- 
ments mean? They mean that if cast inlay fillings are to be made 
in a truly scientific manner pure gold must be used. There are also a 
great number more of clinical reasons favoring the use of pure gold. 



CEMENTS AND MANIPULATION 



381 



" But what is to be done in cases where more strength is required, as 
in bridge spans, plates, etc.? Choose the lesser of the two evils and 
use coin gold, which is alloyed with copper, and if not melted over 
and over again the gases do not injure its ultimate structure as they do 
silver, zinc, and platinum. 

"Casting against Pick-ups. — One more principle about gold should 
be mentioned, the casting of it to other pieces of gold which are in 
the flask. 

"Without any experience except that gained by blowpipe work, the 
first thought which seems to come to dentists when they wish to cast 
against gold is to bring both the golds to as near the same temperature 
as possible. This process absolutely defeats the object sought. 

"In bringing the flask and its contents up to a bright red heat, the 
enclosed metal is brought to a temperature at which it oxidizes, and 
as there are no means of deoxidizing this surface, a less perfect union is 
obtained when the melted gold is thrown in than when the case is 
heated up to a temperature just sufficient to burn out the wax. This 
temperature does not absolutely burn all the carbon off the enclosed 
gold, and as carbon is one of the very best deoxidizers, the gold is now 
in the very best condition to be welded to other gold. The proper 
scientific method in order to cast to this gold is to bring the melted metal 
up to an excessive temperature. 



Fig. 408 




Jameson's casting machine. 



"Pressure. — The pressure used is an important factor in scientific 
casting. It may be too low to do accurate casting, or, on the other hand, 
too high. The intermediate pressure which is just right can only be 
obtained by automatic controlling mechanism." 



382 



RESTORATION OF TEETH BY CEMENTED INLAYS 



The introduction of the Taggart machine was quickly followed by 
many others, some of them notably ingenious. That by Dr. Custer is 



Fig. 409 




Price's casting machine. 



Fig. 410 



































m , 


■\ 


• 
















ff %ji /" 


''" y---x. 


^~--"-^..: ' '" ". ^ 








Ja , 






**i&r ,m ^ 




^~_ 
















"wrasses! 




■ita^^ 






















■*. J^^ 



Price's casting machine. 



distinctly different from all others because of the fact that the gold is 
melted by electricity. This machine has been withdrawn from the 
market, but was a favorite for some time. 



CEMENTS AND MANIPULATION 383 

Jameson's is again different because the gold is thrown into the mould 
by centrifugal force (Fig. 408). This machine is circular in form, with 
extended arms, on one of which is the mould and crucible for melting 
gold. These are set in motion by releasing a strong spring, forcing 
the arms to revolve at a rapid rate, which throws the gold into the mould. 
This apparatus is very efficient. There are several others of the same 
principle used on lathes and home-made contrivances, which cast by 
holding in the hand and swinging in the air. Dr. Weston A. Price has 
devised a most interesting and effective electric casting machine, entirely 
different in design from all others of that kind, and as it is deserving of 
more than passing notice, Dr. Price's description is given : 

" The centrifugal casting machine shown in Figs. 409 and 410 was 
designed both for experimental and practical work, and is particularly 
satisfactory and efficient for both. 

" The gold is melted to the desired temperature in a crucible in a 
resistance muffle like the muffle of a porcelain furnace. The tempera- 
ture of the gold is indicated by the pyrometer. The muffle and its 
contained crucible are in the vertical position until the instrument is 
started revolving. The cup carrying the investment to be cast into is 
inverted over the crucible. 

" Since the rate of the revolution is a constant factor in determining 
the actual pressure, together with the weight of the column of fluid, 
and the radius of the circle, an indicating needle is geared to the 
driving shaft, and indicates the pressure being exerted by the fluid 
gold. 

" When ready to cast, the head carrying the muffle, crucible, and 
investment is revolved by the hand lever, and the heat remains on 
until it automatically releases itself by a counterweight condensing a 
spring and opening a latch. The gold thus enters the investment at 
high pressure and at the full heat. Twenty per cent, platinum in gold 
can readily be melted in it. 

" Large cups are used for large cases like plates and bridges. 

"It is particularly valuable for casting into hard models, like the 
artificial stone which can withstand a very high pressure without 
distortion." 

The most popular machines, because of their cheapness and simplicity, 
are those of the press or stamping form, and the Seymour is representative 
of that class (Fig. 411). 

The metal is forced into the mould by wet asbestos packing pressed 
over the flask rim. This contact with the heat produces steam, 
which forces the molten metal into the mould. Bridges and full den- 
tures are successfully cast with these appliances. 

Successful casting does not always depend upon the machine employed, 
as due consideration must be given to the technique and the quality 
of materials used such as wax and investment. These articles are as 



384 



RESTORATION OF TEETH BY CEMENTED INLAYS 



varied as the machines and their merit depends largely on the manipu- 
lator, although it is now generally conceded that an investment composed 
of three parts of powdered silex to one of best impression plaster will 
give the best results under all circumstances. 



Fig. 411 




Seymour's casting much 



ALEXANDER'S METHOD OF MAKING GOLD INLAYS 



This is a simple and rapid way of making gold inlays, and with a little 
experience, accurate results can be obtained. A plastic mouldable gold 
is made especially for this purpose, and is used in the following manner: 
Tear from the plastic gold matt a piece of gold of sufficient size and, com- 
press into a double-headed cone, using the greatest force possible with 
the fingers, then introduce it to the cavity prepared as in Fig. 412. 
These cavities in bicuspids and molars are prepared with a retention pit, 
differing from other cavities formed for inlay work. The cavity and gold 
are kept dry until the gold is packed with instrument pressure, using 
various sizes of burnishers for this purpose. The gold being very plastic 
it can be handled similar to a wax impression, noting the occlusion and 
finishing the surface in the same manner. 

If the gold pellet is deficient in size it can be added to providing the 
surfaces are dry when the form is complete; it is then removed from the 
cavity and invested. The investment is made to form a slight crater- 
shaped gateway through which the gold solder enters when placed and 
fused upon this surface (Fig. 413); 20 or 22 k solder should be used 



ALEXANDER'S METHOD OF MAKING GOLD INLAYS 385 

for solidifying, cut into small squares and mixed with freshly ground 
crystal borax. 



Fig. 412 



Fig. 413 





A, plastic gold for making inlays; B, 
portion of plastic gold moulded into a double 
cone; C, the same teased into approxi- 
mately the shape of the cavity; D, fused 
inlay, showing excess of gold in button at 
the left; E, cavity prepared with flat 
seats, a and b, to support the inlay. 



Soft iron loop, as made and as embedded 
in position on the investment, in the 
crater of which is seen the plastic gold 
ready to receive the solder. 



Fig. 414 




Soldering apparatus: Adjustable gas-burner, soldering frame and support, with investment in 
position, with the flame properly applied. The ring for confining the flame is placed on the wire 
frame around the investment and another wire frame on top of the ring. 



The piece is slowly heated over a Bunsen burner (Fig. 414), then with 
a broad brush flame from the blowpipe, causing the solder to fuse and 
be absorbed by the gold within the investment. Before seating the 
inlay, it should be finished with a corundum wheel, being careful to 
trim away all overlaps along margins. 
25 



385 RESTORATION OF TEETH BY CEMENTED INLAYS 

No time whatever is lost in making inlays by this method, as the heat 
is applied while the investment is green. The paper upon which it is 
made is burnt up in the process of solidification. Sump is used for the 
investment, as it does not disintegrate from immediate application of 
heat. 

MAKING INLAYS BY THE SWAGING PROCESS 

While the majority of porcelain workers are satisfied that the best 
results are to be obtained by working directly on the tooth from start 
to finish, it is claimed by others that results equally as good may be 
had by swaging, or by what was originally known as the water-bag 
process, introduced a few years ago by a London manufacturing firm. 

The system has some ardent supporters who claim that by it the 
presence of the patient is needed only for the impression and the finish of 
the inlay, the rest of the operation being done in the patient's absence 
and by a laboratory assistant if so desired. The claim is plausible, and 
from the fact that many dentists use this process, makes it worthy of 
consideration. 

Dr. T. T. Van Woert is an ardent supporter of this form of operating, 
and in a recent article on this subject says: "The essentials necessary 
for securing an accurate impression of any cavity are (1) suitable trays; 
(2) proper impression material, and (3) a knowledge of its manipulation. 

"The material for trays which have given me the most satisfaction is 
sheet platinoid of 32, 34, and 36 gauge, because it has a rigidity, together 
with more pliability than any other metal than I have been able to find. 
Another very good quality, while not essential, is that it has a finely 
finished surface, which at least has the appearance of being clean, and is 
pleasing to the patient. The second requisite is the impression material, 
and while it is a matter of opinion, personally, I prefer that made by 
the Detroit Dental Mfg. Co., because it softens at a lower temperature, 
sets quicker, and when cold is as hard if not harder, and gives a very 
much sharper definition of detail than others I have tried. After forming 
the tray, a suitable quantity of compound heated, the tray held over the 
flame until it is hot enough for the material to adhere to it, and the 
compound then pressed into a cone-shaped mass with the fingers and 
then chilled. The surface of the cone should be held in a small flame, 
so that it is quickly heated to the point of running, and then forced 
into position, and either compressed air or cold water used for setting it. 

"I find it a great advantage in large cavities in molars and bicuspids 
to force between the tray and adjoining tooth the blade of a thin cement 
spatula to bring up a sharp line at the cervix. This is easily removed 
after the chilling, and facilitates the removal of the impression as well. 
This is frequently advantageous in approximal cavities of the anterior 
teeth also. 



MAKING INLAYS BY THE SWAGING PROCESS 387 

"Method of Making Amalgam Models. — If we have succeeded in 
securing an accurate impression, it is only the beginning of a successful 
ultimate result, and the next procedure, that of making the model, 
requires as careful consideration and manipulation as any part of the 
technique. Various materials have been recommended for this purpose, 
all of which I have given a most careful and impartial trial, and I am 
forced to the conclusion that there is but one reliable material, and that 
is a good amalgam. When I say 'a good amalgam/ I mean one having 
good edge strength, as little shrinkage as possible, and the property of 
setting quickly, although this is not essential. I use the standard alloy 
made after one of Dr. Black's formulae. 

''First the impression must be embedded in plaster to a sufficient 
depth, and with enough body surrounding it to permit of pressing the 
amalgam well down into the impression. The amalgam is then mixed 
with enough mercury to make it very plastic, and this is burnished into 
place with suitable instruments until the impression is filled. Then the 
excess of mercury can be eliminated by folding a piece of rubber dam 
several times, and placing it on the amalgam and pressing upon it with 
the thumb. 

"The mixing of the amalgam is one of the most important points in 
the procedure. In my early efforts I tried to fill these impressions as I 
would a cavity in a tooth, and the force required in burnishing it to place 
invariably marred the impression which resulted in an imperfect model 
of the cavity. 

"Advantages of Impression Method.— If we succeed in getting an 
accurate model, a filling made to fit it must fit the cavity which it repre- 
sents. This being the case, let us consider the advantages to be derived 
from the impression method: First, we are none of us so perfect in any 
branch of our art that we are not liable to make mistakes. Second, it is 
beyond question that we all have many accidents that are just as deplor- 
able as the mistakes we might make, and when such happens in the 
direct method of making inlays, we are obliged to acquaint our patients 
with the fact that we have erred, or met with a misfortune in the form 
of an accident, either of which is humiliating to the operator and fre- 
quently exasperating to the patient, and, occasionally, to such an extent 
that the patient loses confidence and seeks service elsewhere. 

"We will take, for example, porcelain restorations. In the direct 
method, where the matrix is burnished to the cavity, which, by the way, 
is a much more tedious operation than that of taking an impression, 
we have confronting us the possibility of some distortion in its removal, 
or, perhaps, in the handling after it has been successfully removed, as 
well as the possibility of warping in the fusing of the porcelain itself. 
There is still further the difficulty which arises in many cases of securing 
a suitable color, or just the proper form of contour, all of which is a large 
combination of defects which remains to be explained to the patient. 



388 RESTORATION OF TEETH BY CEMENTED INLAYS 

"The impression method eliminates all of these difficulties. In the 
first place, the matrix is secured by swedging the gold into the die with the 
Brewster press, and the swedged matrix is less likely to change its shape 
when removed than the burnished one. The shape of the swedged 
matrix can be retained by filling it with a hard wax; it is then removed 
and invested, and later the wax washed out. Should the filling prove 
a failure, another, or several others, if necessary, can be made without 
the patient's knowledge; and where the question of color or contour is 
liable to cause trouble, several fillings, varying from a light to a dark 
shade, can be made; or if it be a troublesome contour, several of different 
shapes, so that when the patient presents, the suitable filling can be 
selected without subjecting him to another or several operations, and 
without the unnecessary loss of time to the operator. 

"Cast-gold Fillings. — The same procedure is applicable with cast- 
gold inlays, with the exception that the wax filling is fitted to the tooth, as 
described by Dr. Taggart, omitting the final carving of detail in bite and 
contour which should be done to the die. If the die is correct, the wax 
filling will go to place without difficulty; but one is surprised to note the 
little defects in the filling, such as here and there a small point where 
the wax has not conformed to the sharp edge of the cavity margin. This 
is due to the lack of resistance at such places ; the wax being of one tem- 
perature throughout its entire body, it is forced by the occlusion from 
inward out, and on a line with the cavity margin. It may be said that 
this defect can be remedied by running a hot spatula around the line, 
but I have found this extremely difficult, particularly at the cervix. It is 
also claimed that such defects may be corrected by burnishing the gold 
casting after it has been cemented to place. This has proved just as 
difficult and unreliable in my hands; and it is a potent point that these 
difficulties do not exist when cast fillings are made from the impression 
and amalgam model properly constructed." 



THE BREWSTER PRESS AND MATERIALS 

The cavity is prepared as described for the usual method, edges square, 
margins strong, and without undercut. Talcum powder is rubbed into 
the cavity and adjacent surfaces. 

Then an impression is taken in cement. This is invested in plaster 
of Paris, and the surplus cement which extended around the tooth on 
both sides of the cavity is trimmed away to about one-sixteenth of an 
inch from the margins. Additional cement is then mixed to a very stiff 
consistency, the fingers being dipped in talcum powder and the cement 
well kneaded. The first impression is surfaced with talcum, and this 
second mix pressed into the first one and allowed to stand until quite 
hard. Then separate and invest this second impression or model in one 



THE BREWSTER PRESS AND MATERIALS 



389 



of the steel cups, in plaster, or, if preferred, in one of the very shallow 
cups, in cement or sealing wax. Invest so that the centre is slightly 
higher than the edges of the cup. When the plaster is hard, place a 
square piece of platinum (one one-thousandth of an inch thick) on the 
cement model. With pledgets of cotton wool press the platinum down 
into the cavity; put into the swager, with a water bag over the wool, and 



Fig. 415 



Fig. 416 





Fig. 417 



Fig. 4 IS 





swage. Remove from the swager and burnish out wrinkles or folds; 
then anneal well in the furnace, replace on the model and re-swage with 
water bag, but without the wool. Reverse the press handles, remove the 
cup from the cylinder, and examine the matrix. If any wrinkles or folds 
still remain on the margins, they must be burnished out; and if the matrix 
does not appear to be perfectly adapted to all parts of the cavity, it should 



390 



RESTORATION OF TEETH BY CEMENTED INLAYS 



be again annealed and then subjected to harder pressure in the swager. 
Any crack in the matrix at the bottom or near the bottom of the cavity 
will not affect the fit of an inlay. 

In building in the porcelain where the cavity is a large one, first grind 
an " inlay rod" to fit tightly across the matrix at its widest part; surround 
this, except upon its upper surface, with foundation body; and when it 
is quite dry, bake. Keep the foundation body sufficiently away from 
margins to allow for the thickness of enamel body necessary to produce 
the desired color. When baked, return to the model, and if in baking 
the foundation body has caused any change in the fit of the matrix, the 
next swaging will correct it. After this last swaging proceed to fill in the 
enamel body. Lay the dark shades in first and bake; then add the lighter 



Fig. 419 








1 fi 


~^% . 


MOOELCTE 


A - 


OB CEMENT 

MOLDINE. 


*f 


IMPRESSION 








I BOTTOM 







colors necessary to finish. The foundation body first baked in the 
matrix will prevent any change of form during the baking of the enamel 
body. 

The press should be screwed to the bench. The solid rubber is for 
swaging heavy metal cusps and also for inlays. Should a water bag 
break, carefully dry out the cylinder and plunger. Do not allow any 
rust to accumulate in the cylinder. The inlay rods above mentioned are 
made of high fusing material and are of assistance in large contour work 
by other methods. 

The most recent appliance for this process is the Roach model press 
with trays which are cut to form of cavity and are recommended for 
bicuspids and molars. 



CHAPTER XIV 

THE TREATMENT AND FILLING OF ROOT CANALS. 
By OTTO E. INGLIS, D.D.S. 

The treatment of root canals necessarily depends upon the patho- 
logical condition encountered. This may consist simply in the necessity 
for removal of a perfectly healthy pulp for mechanical or prophylactic 
reasons, or it may involve the treatment of profound disease, such as 
apical or even more complicated abscess. Each case therefore must be 
considered by itself, yet for the purpose of this chapter, root canal cases 
may be divided into three classes: (1) Those in which the pulp is 
entirely or in part vital; (2) those in which the pulp is dead; (3) mixed 
cases. Cases of each class may be either septic or non-septic. 

CASES IN WHICH THE PULP IS VITAL 

These cases will be considered under the following separate sub- 
headings : 

A, Cases of Healthy Pulps Covered by a Sufficient Layer of Dentin. — 
Not infrequently the removal of a healthy pulp is demanded for the pur- 
pose of permitting better anchorage of fillings or inlays by means of pins, 
screws, etc. The use of dowelled crowns, the fixation of a bridge at one 
or more piers by means of devices involving the use of pins anchored in 
root canals, or the growing practice of previously devitalizing and treating 
the canals of such teeth as are to receive hollow metal crowns as bridge 
anchorages, demands pulp removal. Such pulp removal followed by 
proper canal treatment is not only warrantable, but advisable in many 
cases as against other methods of procedure, each case to be considered 
upon its merits. 

B. Cases of Pulps Covered by Sufficient Dentin, but Exhibiting Evi- 
dences of Irritability. — In some cases the recession of the gum may cause 
an irreducible hypersensitivity of the dentin which may have been 
produced by the action of scalers or by the contact of food masses with 
the necks of teeth, or caries may have resulted of such extensive char- 
acter as to keep the pulp in such a state of irritability as to permit 
constant reactions to cold or sometimes hot substances taken into the 
mouth. 

(391) 



392 TREATMENT AND FILLING OF ROOT CANALS 

Not infrequently the pain associated with the excavation of such 
cavities, together with the possibility that thermal shocks will continue 
after filling, indicate the removal of such pulps. Deeper cavities of decay 
sometimes permit the impress of temperature changes or the irritation 
of sweet, salt, or acid substances which cause profound arterial hyper- 
emia of the pulp, with its loss of tone in the bloodvessels, followed by 
their expansion by the pressure of the blood in them. In such cases 
venous hyperemia of the pulp may ensue. 

The condition of determination of blood to a pulp or arterial hyper- 
emia also occurs in consequence of the presence of large metallic fillings 
near a pulp; deep erosions or abrasions; metallic crowns on teeth con- 
taining vital pulps; leaking fillings producing a septic irritation of the 
fibrils, but a non-septic irritation of the pulp body; fractures exposing 
the dentin; pyorrhea upon sound or filled teeth; also infected socket or 
aphthous ulcer; near proximity of an abscess upon another tooth ; blows 
and reflex irritations from other teeth. 

Some of these conditions require removal of the pulp. The reflex 
cases due to contiguous inflamed areas, the excess of blood in them 
overflowing into an otherwise healthy pulp, require, as a rule, attention 
to the causal condition rather than to the symptoms. 

When venous hyperemia follows arterial hyperemia, it is due to com- 
pression of the vein at the apex, preventing a return of blood to the 
heart. The vessels expand greatly, diapedesis of red corpuscles may 
occur, and the pulp usually dies, so the prognosis is bad. 

The necessity for devitalization depends upon the mechanical pro- 
cedures to be carried out and also upon the response to sedative and 
protective therapeutics, if a preliminary trial of the same has been 
considered advisable. 

Arterial hyperemia which has followed the introduction of a metal 
filling, and especially of a large gold filling or inlay, and which becomes 
increasingly profound, so that slight thermal changes cause the patient 
great discomfort, indicates, as a rule, the devitalization of the pulp, it 
being assumed that sedative therapeutics are inapplicable or liable to 
be ineffective. The same is true of vital teeth carrying metal crowns. 

Secondary dentin and pulp nodules are in themselves associated with 
degeneration of the dental pulp, but may lead to further degeneration, 
so that reflex disturbances may be produced. Reactions to thermal 
shock may or may not be in evidence, though they usually are. 

If discomfort be produced by this the pulp should be removed. 

Idiopathic hyperemia sometimes appears in a single tooth. The 
cause being difficult, if not impossible, of determination without pulp 
extirpation, this should be done. 

C. Cases of Pulps Recently Exposed. — The removal of a last layer of 
decalcified dentin, or sometimes of disintegrated dentin, or careless 
excavating, may cause the exposure of a pulp. Unless capping be 



CASES IN WHICH THE PULP IS VITAL 393 

for some reason indicated, the extirpation of the pulp is indicated. 
When decalcified dentin in some mass has been removed from over 
the apparently healthy pulp horn, the pulp itself may for prac- 
tical purposes be regarded as aseptic and possibly hyperemic, while if 
exposed by decay or covered by boggy, infected dentin it may be 
regarded as superficially infected and inflamed. In no case can 
the character of the infection be determined without microscopic 
examination, unless pus be actually present, when, of course, pyogenic 
organisms must be in the pulp. In either case an antiseptic sedative, 
such as phenol camphor or eugenol, should be placed against it for a 
short time. Whether the extirpation shall be under cocain anesthesia 
or after the use of arsenic depends upon the circumstances. As a rule, 
pressure anesthesia with cocain is a safe method. 

In the forgoing classes of cases cocain pressure anesthesia is usually 
the most prompt method of preparing the pulp for removal. 

W r hile an exposed pulp should, as a rule, be removed, two conditions 
may be excepted : First, when the exposure has occurred during excava- 
tion of leathery decalcified dentin in fully formed teeth and the pulp 
seems uninfected and without marked hyperemic reaction. Even here 
it is better to confine conservation to anterior teeth in patients of good 
physical condition for the sake of maintaining the translucency of the 
teeth. The second condition exists when a root is, in all probability, 
not fully developed or very much resorbed, and the pulp should be 
conserved in order to permit it to perform its share in the develop- 
ment or resorption of the root. Even though it be exposed by caries 
and be infected or irritated, the chance of saving it for this purpose 
should be taken. The open character of the root end and the size of 
the pulp favors the distribution of any hyperemia which may exist or 
arise. In any case the pulp is expected to cover itself with secondary 
dentin or to lie quiescent against the capping material, and either result 
may accrue, as subsequent uncovering of pulps comfortably capped for 
several years has shown. 

These advantages have several offsetting disadvantageous possibilities 
which render capping ordinarily inadvisable except for the object stated 
above. These are: 

1. Possible death of the pulp through hyperemia due to thermal 
changes. 

2. An overproduction of secondary dentin,, the production of pulp 
nodules, or other degenerative changes, the pulp becoming exhausted 
and death ensuing. Increased difficulty of subsequent canal treatment 
may result. 

3. Disease of the pulp due to infection beneath the capping material. 

4. The time required for assurance of success or failure. 

From the foregoing it will be seen that a pulp capping should be a 
non-conductor of thermal changes and antiseptic or even germicidal in 



394 TREATMENT AND FILLING OF ROOT CANALS 

character; it should also be rigid, sedative, and applicable without press- 
ure, of which a pulp is intolerant, as it is a mechanical cause of pulp 
irritation. These needs are all met by the use of a sedative antiseptic 
cement. A mixture of zinc oxid and thymol made while the latter is 
melted makes a capping fulfilling these conditions. A small piece of 
the solid mixture is melted and a portion carried on a burnisher or 
within a metal cap to the pulp. A crystal of thymol placed on this 
will hasten the setting of the mass. Another good example is Jodo- 
Formagen, which contains phenol, eugenol, and formaldehyd, together 
with iodin salts. While the exact formula is not published, its value 
is amply proved. It may be applied either with or without a metal 
cap. It is preferable, as a rule, to use a bit of paper to carry the paste 
to place, later removing the paper, or to flow it gently over an exposure 
and adjacent dentin by means of a ball burnisher. It soon sets, and 
when rigid fulfils the object of a metal cap, namely, a protector against 
the pressure of material subsequently introduced. As a rule, it is better 
to cover it w T ith zinc phosfate to which about 5 per cent, of powdered 
thymol has been added. 

The manner of using the cement depends upon the amount of reten- 
tion and the character of the metal filling. When amalgam is to be 
used there is often advantage in making a combination filling in which 
soft cement is placed in the cavity and amalgam pushed into it in such 
a way as to distribute the cement about the cavity and retentions as 
a thin lining adhering both to the walls and to the amalgam. Under 
conditions which allow of a large mass of cement, this may be made 
quite stiff and be gently packed into the cavity, approximately shaped, 
and, when set, finally shaped to form a supporting intermediate or 
base for the filling. 

Other capping cements of less value are oxysulfate of zinc, plaster 
of Paris, and oxychlorid of zinc. The first consists of a mixture of 
uncalcined zinc oxid and a saturated solution of zinc sulfate in 
distilled water. The plaster of Paris should be mixed with a 1 per cent, 
aqueous solution of formaldehyd. The oxychlorid consists of calcined 
zinc oxid for the powder and a solution of zinc chlorid for the liquid. 
The liquid should be modified by the addition of distilled water in the 
proportion of two parts of the liquid to one of water. A trifle of iodoform 
or hydronaphthol may be added to any of these cements. 

When a lesser condition than exposure exists, or, in other words, 
a condition of almost exposure, the condition of the pulp should be 
considered, and if there has not been too much irritation, the pulpal 
wall may be covered with Jodo-Formagen or thymol and zinc and the 
balance of the cavity be filled with a temporary cement filling. The 
subsequent comfort or irritability of the pulp will decide as to whether 
to fill the tooth or devitalize the pulp. In all other cavity conditions 
there can be no question as to the advisability of pulp conservation 



CASES IN WHICH THE PULP IS VITAL 



395 



Fig. 420 



provided there be no symptoms of unusual pathological disturbance of 
the pulp. 

There may be slight or pronounced hyperemia of the pulp following a 
capping operation which may be treated by means of counterirritants 
applied to the gum every other day. If successful, the irritability of 
the pulp will gradually subside and the tooth will bear hotter and colder 
applications until a comparatively normal tolerance is reached. Jack 
has formulated the plan of testing the sound lower incisors while under 
a rubber dam with hot and cold water of known temperatures until pain 
is produced, this being regarded as the normal limit of thermal toler- 
ance. He has shown that individual reactions differ, pain being pro- 
duced at from 74° to 32° F. on the cold side, and at from 118° to 152° F. 
on the heat side. The data gained by this test may justly be termed 
the thermal index of the patient, and is a guide in judging the cure of 
the hyperemia. Of course, if a failure results, the hyperemia will become 
severe, and there will be increasing response to thermal shock. 

D. Cases of Vital but Septic Pulps. — Vital pulps may be infected from 
one of three possible directions. First and most frequently by way of 
the orifice of the pulp horn or orifice of 
exposure in case of a cervical cavity. The 
infecting organisms may traverse either 
decalcified or disintegrated dentin overlying 
the pulp, but quite a considerable num- 
ber of cases have been observed to have 
followed the dentinal tubules beneath a 
filling or to have penetrated spaces exist- 
ing in secondary dentin. The layer of 
dentin penetrated may be nearly one-quarter 
of an inch in thickness. Without question 
the organisms have caused decomposition of 
the fibrils in their passage to the pulp. In 
such cases as this partial suppuration of 
the pulp may ensue (more rarely partial 
gangrene), and the pus is confined by the 
dentinal wall. The pathology is that of 
abscess when the dentin so confines the pus 

(Fig. 420) . The removal of boggy dentin from over a pulp horn may allow 
a droplet of pus to escape, and in more rare cases a copious flow of pus 
occurs. Sometimes the abscess is confined within the body of the pulp, 
which has a white or yellowish- white appearance, the pus only escaping 
after puncture (Fig. 422). When the pus is confined, either by dentin or 
the body of the pulp itself, the symptoms are the same, namely, a delayed 
but intense reaction to heat, due to expansion of the gases against the 
pulp, with relief from cold applications due to the contraction of the 
gases. The reaction to cold is sometimes present in the milder forms, 




Abscess of the pulp after forma- 
tion of a large amount of secondary 
dentin, dividing the pulp into two 
portions: SD, secondary dentin; 
VP, vital pulp; AP, abscess or 
confined pus; J, area of apical 
inflammation. (Diagrammatic.) 

(After a case in the mouth.) 



396 



TREATMENT AND FILLING OF ROOT CANALS 



especially when a deep cavity is present. The peculiar sporadic cessation 
and reappearance of the pain when the pulp is not subjected to thermal 
changes is also characteristic. The pathology of abscess (a circum- 
scribed cavity containing pus) is applicable to such cases as these, and 
a diagnosis of such condition from the above symptoms is warrantable. 
When the infection has destroyed a portion of the pulp by suppuration, 
or other putrefactive process, but the egress of the pus, etc., is effected, 
owing to an open pulp cavity, the pyogenic erosion of the pulp may 
proceed until even only a minute portion of pulp may remain vital but 
evidently infected. This is known as ulceration of the pulp, because it 

Fig. 421 




A, diagram of lower molar with caries at a which exposes the pulp; the darkened portion at 6 shows 
the extent of the inflammation; the rest of the organ was free from inflammatory change; B, illustra- 
tion of the inflamed tissue, showing a part destroyed by suppuration at a; the odontoblasts are under- 
mined at b. the bloodvessels which were filled with blood clot in the section are left blank here, that 
they may be more apparent. (Black.) 



consists of an inflamed and open breach in the continuity of the pulp. 
The symptoms are not, as a rule, severe, consisting of gnawing local pain 
or possibly of reflex pain in other parts (Fig. 421). 

When food is packed into the cavity the pus and gases become con- 
fined and the symptoms of abscess of the pulp may appear. 

The writer has often found such pulp remnants under faulty canal 
fillings, in one case after the roots of a molar had been partially filled 
for twelve years. In some cases partial gangrene of the pulp has been 
found, due sometimes to neglected cases of arsenical application, at 
others to the production of venous hyperemia with death of the pulp 



CASES IN WHICH THE PULP IS VITAL 



397 



bulb only, and in still others the pulp in one or more roots of a molar 
has remained vital while the pulp in another root has undergone com- 
plete moist gangrene. 

Ftg. 422 




Acute suppurative pulpitis in the coronal portion: J. intensely inflamed horn; .4, absce??: V, 
bloodvessels engorged with blood; 8, superficially inflamed horn; N, nest of inflammation. X 10. 
(Bodecker.) 



The second avenue of infection of a pulp is by way of the apical 
tissue. An apical abscess on a root of an adjoining tooth may by exten- 
sion of its pus cause apical infection of the pulp of another tooth. This 
will cause prompt death of the pulp of a single-rooted tooth, but may 
only cause inflammation of the pulp of a multirooted tooth. 



398 



TREATMENT AND FILLING OF ROOT CANALS 



The most frequent cause of apical infection of pulp is, however, 
found in cases of deep pyorrhea pockets. The infection having reached 
the apex causes such an infection, which travels downward into the 
pulp of the denuded root. This pulp filament may be dead or partly 
vital, while the filaments in other roots remain vital and inflamed. 

The third direction, or infection by way of the blood stream, is a 
possibility, but the condition is only inferential when the case is one 
associated with some general or profound local infection. 

E. Hyperplasia of the Pulp.— The exposure of the pulp leads some- 
times to a chronic constructive inflammation of its tissue. The pulp 
extrudes into the cavity of decay, often filling it. Such a pulp may be 
suppurating upon its surface, and at times it seems to have removed 
the decay from about it as though the walls had been subjected to a 
resorptive action. 

The clinical appearance varies considerably (Figs. 423 to 428). 



Fig. 423 



Fig. 424 



Fig. 425 



Fig. 428 



ttir 




Hypertrophy of pulps. (Garretson.) 



Fig. 427 



Fig. 428 





Hypertrophy of the gum. (Garretson.) 



Hypertrophy of the pericementum. (Garretson.) 



The hyperplastic portion of the pulp may be frozen with ethyl chlorid 
of saturated with trichloracetic acid and ablated. The balance of the 
pulp usually succumbs to arsenic. The covering is best made in cases 
with little cavity retention by driving a fair-sized wheel bur into the 
side of the concave cavity. A thin, flat piece of spunk is then laid 
upon the pulp and an amalgam covering built into the cuts made by 
the bur. Next, the amalgam is cut through and the spunk gently un- 
covered and removed, leaving a central opening in which arsenic may 
readily be sealed. The location of the polypoid growth and the condi- 
tion of the tooth surrounding it, will generally distinguish it from a 
polypoid gum. If uncertain, it should be pressed away with cotton 
before applying arsenic. 



METHODS OF PULP REMOVAL 399 



METHODS OF PULP REMOVAL 



There are four general methods by which a patient or pulp may be 
prepared for the operation of extirpation. These are as follows: 

1. Anesthetization of the patient and removal of the pulp during 
the period of anesthesia. 

2. Anesthetization of the pulp by cocain, or in some cases by nervo- 
cidin and the removal of the pulp. 

3. Anesthetization of the apical tissue and removal of the pulp. 

4. Devitalization of the pulp followed by its removal. 

1. General Anesthesia. — The pulp of a single-rooted tooth may be 
readily extirpated while the patient is anesthetized by nitrous oxid, 
nitrous oxid and oxygen, or by somnoform. The instruments should 
be in readiness, the patient anesthetized, the pulp uncovered by an 
engine bur, and the pulp extirpated with a barbed broach or Donaldson 
cleanser. 

In cases of multirooted teeth the available anesthetics are ether, 
which is rarely used for the purpose, and nitrous oxid administered 
by nasal inhalation. The latter is accomplished by means of a special 
apparatus having a hood covering the nose, of which the Teter appli- 
ance is the most notable example. This is designed to prolong the 
anesthesia by administering nitrous oxid and oxygen. As it is equally 
applicable to the otherwise painful excavation of cavities of decay and 
extractions, it is a valuable means for accomplishing this purpose also. 

The ordinary outfit is, however, of value by enabling the operator to 
remove the diseased bulb of the pulp of a multirooted tooth, after 
which and while the patient is conscious other methods of removal 
of the radicular portions of the pulp may be employed. 

2. Anesthesia of the Pulp. — For this purpose cocain is almost univer- 
sally employed. There are three practical methods by which it may be 
introduced into a pulp : 

(a) By pressure accomplished by means of raw vulcanite. A strong 
solution (50 per cent, to saturated solution) of cocain hydrochlorid 
is made in water, or preferably in some mild antiseptic solution 
which does not cloud on admixture. A small piece of amadou (spunk) 
is saturated with it and laid upon the orifice of exposure. The cavity 
is filled with the rubber, and upon this is placed a flat-ended plugger or 
burnisher broad enough to concentrate the force upon the amadou. 
A broad piece of amadou placed over the rubber is sometimes of assist- 
ance in preventing the slipping about of the rubber. Gentle pressure 
is now made and a slight pain is usually felt. The pressure should be 
maintained until this passes away, then it is increased little by little 
until some force is exerted. The rubber and amadou are then removed, 
the pulp cavity opened, the progress of the anesthesia tested with a 



400 TREATMENT AND FILLING OF ROOT CANALS 

fine broach, and the pulp lifted away. Some prefer to place a prepared 
pellet or crystal of cocain upon the pulp. 

For multirooted teeth the pressure should be prolonged, and to 
prevent return of sensation and hemorrhage while extirpating it is well 
to instil carbolic acid into the pulp tissue by means of a fine, smooth 
broach. 

In some cases the operation fails because the direction of the pressure 
has been away from rather than toward the pulp or because the spunk 
has slipped from its place. Sometimes the orifice of exposure may be 
enlarged, but as sensation is discovered a fresh application must be 
made. 

Sometimes repeated applications fail of effect, though the application 
is not painful, and at times the pressure is not tolerated at all, owing to 
the irritability of the pulp. In cases of cavities without walls to con- 
fine the rubber, it is well to enclose the buccal and lingual embrasures 
with the thumb and forefinger. In very broad occlusal cavities the finger 
tip confines the rubber nicely. 

When only canal filaments are present, any septic matter should 
be removed by syringing repeatedly with an antiseptic solution; then 
the canals should be thoroughly dried, and the cocain, dissolved in an 
antiseptic, is carried on a cotton thread into the canals and against 
the pulp remnant. A small piece of rubber is placed in one canal and 
the pressure confined to that canal by means of a plugger which will 
about fill the canal . The action is then repeated in the other canals. This 
produces better results than a general pressure over all the canals at 
once. 

If used after arsenic has been applied the results are not usually so 
good, but sometimes the method is successful. To avoid the introduc- 
tion of arsenic into apical tissue all sloughing portions should be removed. 

When the pulp is not exposed, the application to the dentin over the 
pulp permits advance, a pocket being created in the dentin with a bur, 
which aids the further instillation of the cocain; finally, the pulp is 
exposed and the anesthesia is completed. 

Clyde Davis recommends for the purpose of producing the exposure 
the use of a drop of 1 to 1000 adrenalin chlorid followed by a drop of 
37 per cent, formaldehyd, then pressure with raw vulcanite. 

There is a possibility of the introduction of cocain into the general 
circulation, and some systemic effect may be noted, though often this will 
be due to the agitation of the patient. Some patients have complained 
of tingling in the fingers. If syncope be threatened aromatic spirit of 
ammonia should be administered, the head lowered, the feet elevated, 
and smelling salts or amyl nitrite applied to the nostrils. 

Hemorrhage following the extirpation of the pulp is sometimes 
copious. To avoid this, carbolic acid should be instilled into the pulp 
tissue bv means of a smooth broach. A fine Donaldson cleanser may 



METHODS OF PULP REMOVAL 401 

be passed to the apex of the canal and slowly twisted, the operation 
consuming several minutes. This torsion of the pulp largely limits the 
hemorrhage. If it occurs it should be allowed to check itself, although 
if desired a trifle of a mixture of powdered alum and powdered thymol 
may be taken upon cotton wet with phenol-camphor and passed to the 
end of the canal. Deliquesced zinc chloride checks hemorrhag promptly, 
but its application may be painful. 

It is an open question whether canals from which living pulps have 
been removed should be filled immediately or not. There is liable to 
be a secondary hemorrhage, particularly when adrenalin is used with the 
cocain. Many prefer to fill at once, claiming that surgical pericementitis 
is the only result. The writer, as a rule, wraps a twist of cotton upon 
a Swiss broach, dips it into phenol-camphor, then into formocresol, 
and applies it to the canal. This, as a rule, permits the healing of the 
parts without much tenderness, and really consumes but little more time 
in the aggregate. Moreover, the formocresol tends to mummify the 
fibrils left in the dentinal tubules. 

As an alternate upon the immediate filling side a paste of 

T$ — Thymol 1 part 

Paraform 1 part 

Zinc oxid 1 part 

Glycerin 1 part 

may be used with gutta-percha cones to accomplish the same result. 
All work should be done under aseptic precautions. Where applicable 
and not liable to be too painful, the rubber dam should be applied. 
The writer often uses napkins instead, and relies upon the carbolic acid 
instilled into the pulp and the formocresol dressing to maintain 
asepsis. This is repeated if the cavity be douched out. 



Fig. 429 




The Myera compound syringe for forcing cocain solutions through the dentinal tubules. 



(b) When considerable dentin overlies the pulp, or when a tooth is 
sound, the most expeditious method of cocain anesthesia is by means of 
the compound syringe (Fig. 429) . This consists of a strong metal syringe, 
the piston of which is actuated by means of levers which multiply the 
power of the hand. The Myers syringe is one of the best, although several 
forms are obtainable. The syringe nozzle is embedded in a small hole 
26 



402 TREATMENT AND FILLING OF ROOT CANALS 

drilled in the dentin by one of two methods. The hole may be made 
small with parallel sides, as when drilled with a No. J bur. The syringe 
nozzle has then slightly conical sides at the point intended to jam a fit 
when introduced with force into the drill pit. In the other method the 
drill pit is made with a cone-pointed bur or bud bur, and the syringe 
point is made flat-ended, a form easy to maintain upon the point. A 4 to 
10 per cent, cocain solution is sufficient, and all air must be expelled 
from the syringe. It is wise also to expel all air from the drill pit by 
a slight pressure while the syringe point is loosely held in the pit. Then 
a rotary motion under forward pressure embeds the point. 

If no leakage occurs the force of the piston drives the cocain through 
the fibrils in the tubules and into the pulp. The pressure must be main- 
tained for about three minutes. The anesthesia is then tested by drilling 
with a No. i bur in the direction of the pulp. If the dentin be sensitive 
the syringe is to be reapplied. Often the bur sinks into a sensitive pulp 
without warning by dentinal sensitivity. In such case the syringe is 
reapplied for a moment, when, as a rule, the anesthesia will be complete. 
In all cases when testing, the drill hole should not be enlarged, as this 
prevents reapplication. Too much cocain should not be introduced, 
as it has happened that the area about the apical tissue has been pro- 
foundly injected, with, of course, possibility of systemic complication. 
This warning applies to the second application rather than the first. 
When desirable, the enamel of a sound tooth which is to be crowned may 
be ground away until the dentin is reached, or if enamel must be removed 
in only limited degree, as for a tap upon the lingual side of an incisor or 
in the fissure of a bicuspid, a " spot" is first made with a dentate bur, 
then a spear drill is driven through the enamel only just reaching the 
dentin. The drill hole is then enlarged as widely as permissible, after 
which the pit is made in the dentin with a No. \ bur. 

The lingual side of upper incisors will permit of sufficiently direct 
pressure to enable the operator to centre the syringe point, but in many 
cases in which crowns are indicated the labial side may be used with 
advantage, especially at the neck when the cementum is exposed. Later, 
the entrance tap is made in line with the pulp axis. The labial or mesio- 
buccal side must always be used in the lower teeth, unless a cavity be 
used, sometimes preferably at the neck, sometimes higher up. In 
cavities having sufficient dentin over the pulp the pit may be made in 
the pulpal wall, and if for any reason it is needed the drill pit may begin 
at the cervical portion of the cavity and extend into the root dentin 
and parallel with the pulp. The pit must be deeper than the syringe 
point will penetrate, so that the pressure may force the solution laterally 
through the tubules, which are at a right angle to the axis of the pulp 
and the pit. 

The considerations pertaining to the pulp removal are the same as in 
the other forms of pulp anesthesia. 



METHODS OF PULP REMOVAL 403 

(c) The third and least desirable form of cocain anesthesia of the pulp 
consists of its introduction by the cataphoric current. It has the dis- 
advantage of consuming more time, but may serve when patients are 
timid. A 10 per cent, solution of cocain hydrochlorid is applied to the 
pulpal wall of the cavity, the tooth being previously placed under rubber 
dam. The anode of the cataphoric outfit is applied to the cotton and 
the cathode placed in the hand or at the cheek. 

The dentin may be anesthetized as well. If desired, this method 
may be used to obtain a pulp exposure and the pressure method employed 
to complete the operation. 

When beginning with an exposed pulp, about fifteen minutes will be 
required unless hyperemia of the pulp exists, when a longer time will 
be required. As with the pressure method, there may be occasional 
failures. It will be noted that there is advantage in time and con- 
venience in the pressure methods. 

(d) The fourth method of producing pressure anesthesia consists in 
the use of carbolic acid in place of the cocain or in case of obstinate 
canal filaments of a solution of cocain in carbolic acid. 

When pulp nodules or calcific degeneration exists there may be some 
difficulty in introducing the cocain, but after a first or second appli- 
cation the nodule may be lifted away and further pressure made, although 
even at this point failure may occur. 

In all cases presenting difficulty in introduction, desiccation is a 
valuable preliminary. Cook 1 recommends an application of 10 per cent, 
sulfuric acid for a few minutes, followed by sodium bicarbonate pre- 
vious to a reapplication of the pressure anesthesia as highly effective in 
aiding penetration of the cocain. 

(e) The fifth method of producing pulpal anesthesia is by the appli- 
cation of nervocidin, an alkaloid obtained by D. Dalma from the 
East Indian plant gasu-basu. Arkovy recommended that a portion 
be applied to the exposed pulp for twenty-four hours, when it may be 
removed painlessly. Soderberg suggests the addition of a small amount 
of cocain hydrochlorid to overcome the primary irritating effect of the 
nervocidin. He prefers the following combination: 

1$ — Gum arabic 5j 

Zinc sulfate o ss 

i Water fgj— M. 

Dissolve the zinc sulfate in the water, add the gum arabic, stir, let stand for 
twenty-four hours, and strain. 

1^ — Of above solution f 5ij 

Nervocidin gr. x 

Cocain hydrochlorid gr. x — M. 

To a portion of the latter solution add uncalcined zinc oxid to make a cement 
which is placed in the floor of the dried cavity. Cover with cement. If dentin be 
over the pulp, an additional application of twenty- four hours' duration is required to 
obtain an exposure. 

1 Dental Review, 1905. 



404: TREATMENT AND FILLING OF ROOT CANALS 

3. Paralyzation of the Transmitting Apparatus. — The third general 
principle upon which pulps may be extirpated consists in paralyzing 
the nerve filament leading from the pulp to the larger branches of the 
fifth nerve. If the nerve in the apical tissue can be prevented from trans- 
mitting sensation, the operator may remove the pulp surgically without 
pain. The apical tissue is to be located as nearly as possible, the gum 
sterilized, and an injection of about five drops of a 1 per cent, solution 
of cocain containing adrenalin injected as near the periosteum of the 
bone as possible. This is expected to infiltrate the apical tissue via the 
collateral vessels in the bone. To permit the accomplishment of this a 
little time should be allowed. On drilling the dentin to open the pulp 
cavity, one should note the presence or absence of sensation, and upon 
exposure a smooth broach should be used to test the state of the pulp. 
In the use of this method precaution should be taken to administer an 
antidote before using the cocain. What is called diploe anesthesia has 
been employed to relieve the pain of dental operations, and consists of 
cutting to the bone after the above injection, perforating the bone, and 
injecting into the diploeic structure. A method employed by some 
bridge-workers consists in notching and excising sound crowns. It is 
claimed that for a short period after the excision the pulp is insensitive 
and can be lifted away with a broach. If for any reason this should 
fail, other immediate methods can be employed 

4. Devitalization of the Pulp. — Devitalization of the pulp by the use 
of arsenic as a preliminary to its successful removal is the oldest of the 
methods employed at the present day, and, as shown, it still has to be 
resorted to either from necessity or convenience. 

The method has its value in the very teeth in which its use is least 
objectionable, namely, the posterior teeth. There is no danger in the 
use of arsenic in teeth having completed roots or in unresorbed tem- 
porary teeth, provided the arsenic be accurately sealed in the cavity so 
that it does not escape upon the gum. If it does escape it may destroy 
the gum or pericementum and cause partial necrosis of bone or the com- 
plete loss of the tooth together with some bone. The pulp always dies 
through a process of venous hyperemia induced by the protoplasmic 
irritant and poison. This hyperemia is progressive from the pulp 
bulb toward the apex of the root, and there it causes the death of the 
apical portion of pulp through interference with its nutrition. Some- 
times this hyperemia of the pulp extends into the apical tissue, but if 
the pulp be left in situ, necrosis of apical tissue never results, but, on 
the contrary, the hyperemia becomes resolved after the death of the 
pulp. 

The writer fails to see wherein such a hyperemia differs in consequence 
from that produced by the surgical removal of a pulp and denominated 
with favor as surgical pericementitis. In his hands such teeth have 
given quite as good results as when other methods have been employed. 



METHODS OF PULP REMOVAL 405 

By this it is not meant that there has been no difficulty in devitalizing 
some pulps, particularly some of those in which repeated applications of 
cocain under pressure failed to anesthetize, but that when carefully 
handled and sufficient time for pulp death has been allowed, careful 
filling of the canal has been successful. 

The rational objections to arsenic, aside from its escape upon the 
gum, are: (1) The possible production of pain. (2) Possible suffusion of 
the tooth. (3) The time required. 

The production of pain may largely be obviated by observance of 
certain technique. The pulp should ordinarily be exposed and be 
slightly bled to relieve any hyperemia or inflammatory engorgement 
present, as this seems to prevent the absorption of the arsenic. A power- 
ful sedative such as thymol, menthol, cocain hydrochlorid, or morphin 
acetate should be employed as a corrective, and the menstruum should 
be sedative rather than coagulant. All pressure on the pulp should be 
avoided, as this produces pain. 

Sufficient time for complete death should be allowed, say, from a 
week to ten days. If upon examination with a fine smooth broach 
vitality be discovered, a sedative should be applied and pulp death 
awaited. Leaving the dead portion against the vital part of the pulp 
is even better than making a second application, as its removal relieves 
the congestion by opening the vessels, and the congestion is necessary to 
the end in view. If the pulp gives but little response upon probing, it 
may be removed. Sometimes the diapedesis of red corpuscles, asso- 
ciated with the venous hyperemia, causes a staining of the pulp and 
dentinal fibrils with the liberated hemoglobin. This is unfortunate, 
but can be treated by bleaching with 25 per cent, ethereal pyrozone 
sealed in the pulp cavity for about twenty-four hours after the pulp 
is removed. The third objection, the matter of time, does not apply 
to the cases of prompt devitalization, as the time spent in pulpal 
anesthesia and checking hemorrhage is in the aggregate no less than in 
the arsenical cases. In the delayed action of arsenic the objection is 
valid, but the apical injection and general anesthesia methods are still 
open to trial. The arsenical method, of course, requires a longer period 
of treatment. Pulpal anesthesia can be tried when arsenic does not 
act well, but should be avoided when it originally failed. As stated, 
these considerations apply mainly to posterior teeth. 

The following is an excellent formula for arsenical paste : 

1$ — Arsemei trioxidi . gr. xv 

Cocaini hydrochloridi , gr. xx 

Thymolis (vel menthoiis) gr. v 

Olei caryophylli q. s. ft. pasta — M. 

This should be finely ground in a mortar and spread over the bottom of a wide 
glass jar so that some of the paste may be taken up from the bottom. The arsenic 
settles to the bottom. 



406 TREATMENT AND FILLING OF ROOT CANALS 

Buckley recommends the following formula: 

1$ — Arsenic trioxid gr. 180 

Cocain alkaloid gr. 30 

Thymol gr. 15 

Petronal 1U 15— M. 



Fig. 430 



There are some advantages in the so-called devitalizing fiber intro- 
duced by J. Foster Flagg. To make this, absorbent cotton is cross-cut 
with scissors to a fine lint. This is dusted into the paste or ground up 
with it in the mortar. It may then be dried on a blotter and be bottled 
for use. As it lacks long fibers, a small portion may be detached and be 
placed upon the pulp. There are cases, however, in which the paste 
should be carried to the exposure upon a probe and gently inducted into 
a fine exposure. Here its tendency to spread or penetrate is valuable. 
The fiber has no such tendency, which makes it less dangerous in use. 
In making the application a minute portion of paste is to be laid upon the 
pulp, or a pinhead pellet of cotton is rolled in it, the excess of menstruum 
removed, and it is then applied to the pulp, or a portion of devitalizing 
fiber is used. This is then sealed m.. 

The cavity should be prepared for the reception of arsenic, decay being 
removed as far as practicable. 

There are two good methods of sealing the arsenic. In cases not 
approaching the gum, or where dryness can be maintained, the applica- 
tion may be accurately made and quick- 
setting cement flowed over it. This cement 
is capable of being fairly dropped into a 
cavity or led around the periphery by a 
probe, and should be very adhesive, also be 
readily removable. A still safer method 
consists in applying a pellet of amadou over 
a part of the pulpal wall. The cement is 
then introduced about the periphery of the 
cavity, the amadou being left largely uncov- 
ered. When hard, any cement over the 
amadou is removed and the latter lifted 
out, thus leaving a box-like receptacle for 
the arsenic and a pellet of amadou partly 
wet with eugenol in which menthol is dis- 
solved. When placed, the orifice is dried and more cement added. 
This method of first making the covering is of special advantage 
when the cavity cervix is near the gum and prevents the forcing of 
arsenic toward the gum in the act of making the covering. Amalgam 
or facing amalgam may be used in place of the cement (Fig. 430). 

The rubber dam is generally insisted upon, but cannot be used in 
the worst cases, hence an expert may dispense with it. There is a 




Diagram showing method of first 
making the covering for an arsenical 
or sedative application. (See text.) 
EP, exposed pulp; A A, arsenical 
application; C, sedative covering to 
same; A, amalgam placed before 
thes applications; A', amalgam to 
seal them in; E, enamel. 



METHODS OF PULP REMOVAL 



407 



tendency among students to rely upon the rubber dam alone to prevent 
accidents. This is a fallacy, as the same results may occur with it as 
well as without it. The chief danger lies in the use of temporary stopping 
after placing paste. Capillarity and pressure often carry the paste 
to the cervical margin. Making the covering first or using fiber con- 
stitute the best precautions. 

In case of a very dangerous cavity, as a distocervical one, a special 
drill pit known as a " pocket" is to be made at some other point extending 
in the direction of the pulp horn and as near to it as can be made with- 
out too much infliction of pain. In this the arsenic is to be sealed while 
antiseptic sedatives are to be placed on cotton in the cavity of decay. 

The presence of pulp nodules may necessitate an application after 
lifting away the nodule (Fig. 431). 




Calcification of the dental pulp: At A is shown the outline of a lower molar with a cavity at 6. 
The pulp chamber is much reduced in size and filled with calcific material, as shown in B. a, a, large 
granular mass of calcific material, which is very transparent but finely granular. A very few irregular 
iines are seen in the centre, which slightly resemble dentinal tubes; b, an erratic growth of irregularly 
formed and unusually transparent dentin; c, line of the growth of dentin from the floor of the pulp 
chamber — the growth from other directions is so perfectly regular as to leave no markings; d, margin 
of the cavity of decay: e, a bundle of cylindrical forms of calcific material extending down into the root 
canal. These extended to the apex of the root. (Black.) 



The arsenical method may be used after a preliminary general anes- 
thesia and bulb removal, or may even be used against an obdurate 
pulp canal filament. 

Symptoms. — The large majority of pulps die under arsenic with but 
little pain. Sometimes throbbing pain results, passing into a heavy 
fulness as congestion supervenes. If too great, the pulp should be 



408 TREATMENT AND FILLING OF ROOT CANALS 

uncovered and bled slightly, then a sedative should be applied, iodin 
used as a counterirritant upon the gum, and pulp death awaited. Ordin- 
arily the pain passes away as the pulp becomes more fully congested. 
Apical irritation may result and may be ignored if slight, or if severe be 
treated in the same way as the pulp irritation. A guard to prevent 
overocclusion is sometimes useful. 

Accidents from Arsenical Applications. — These are avoidable, and 
therefore only occur as the result of carelessness. In very doubtful 
cases, if a "pocket" cannot be employed the patient should be seen after 
one or two days for observation of the condition of the gum. It is better 
that no escharotics have been applied, as confusion may result. The 
signs of arsenical necrosis at this time are a turgid, purplish, or sloughing 
gum festoon, and if present this should be freely cut away and the 
arsenical application should be removed from the cavity. 

Any exposed alveolar process should be scraped and the parts should 
be kept aseptic with hydrogen dioxid. Applications of dialyzed iron or 
10 per cent, silver nitrate solution will arrest further necrotic action by 
forming insoluble arsenites of the respective metals. 

If the tooth be lost the alveolus should be burred away to tissue 
capable of healthy granulation. If bone become necrotic it usually is 
self-limited, even though it be considerable. The part should be treated 
as above and the exfoliation awaited with this assurance. 

The condition of the roots as to calcification or decalcification may be 
determined by consulting Figs. 432 and 433; and resorbed or incom- 
plete teeth should not have arsenic placed in them, as the arsenic may 
pass through the existing end of the root. 

Special Methods of Preparing Pulps for Removal. — When in the course of 
extirpation a vital apical remnant is found, carbolic acid may be instilled 
into it with a fine, well-sharpened Swiss or other smooth steel broach. 
The canal is flooded with the phenol and the broach is to be repeatedly 
but gently yet progressively thrust into it, carrying with it some car- 
bolic acid. Forcibly pressing the phenol into the pulp filament under 
a mass of unvulcanized rubber, as in cocain pressure anesthesia tech- 
nique, will usually desensitize the filament and facilitate its removal 
without hemorrhage. 

A hot Evans' root drier may be quickly thrust into it. This does 
not necessarily give much pain. Tightly packing a thread of cotton 
saturated with carbolic acid against such a filament and leaving for a 
few days will sometimes induce thrombosis and death of the pulp. 

When a tooth has been fractured or excised, or when the pulp is fully 
and widely exposed in a single root, a Portuguese toothpick finely whit- 
tled and previously soaked in carbolic acid may be quickly thrust into 
it, thus "knocking out" or crushing out its vitality, so suddenly as to 
prevent much painful response. If the removal of the stick does not 
bring the pulp with it, it should be broached out. 



METHODS OF PULP REMOVAL 



409 



Devitalization of Pulps in Temporary Teeth.— All of the anesthetic 
measures are as applicable to temporary teeth as to the permanent ones 
if the little patient will tolerate their application. 



2 2 2 2 * -^ 

cS OS oj oj £ a 




If the child present an exposed pulp in a tooth the roots of which are 
not resorbed, arsenic much diluted may be applied for twenty-four 



410 



TREATMENT AND FILLING OF ROOT CANALS 



hours and then be removed, the pulp being then allowed to die. When 
roots are resorbed it is better to cap the pulp with Jodo-Formagen 
cement, or if necessary apply a pellet of cotton wet with phenol, then 
touched to iodoform and seal in with temporary stopping, making a 
slight pressure. This may remain a week or more and be renewed if 
necessary. 

Darby has used cantharides, -/o" grain in carbolic acid, with success. 
It must be carefully sealed, as strangury is a possibility. 



THE EXTIRPATION OF THE PULP 

After the pulp is prepared for removal or the patient is anesthetized 
free access to all parts of the pulp cavity and canals must be obtained. 
This is usually best accomplished by an opening made in direct line 
with the axis of the pulp canal. In general terms this involves for 
sound teeth an opening upon the lingual surface of incisors and cuspids 
and upon the occlusal surface of bicuspids and molars. 



Fig. 434 Fig. 435 

a 



Fig. 436 Fig. 43: 



$ 






i B 



Fig. 438 



Fig. 439 



Fig. 440 



Fig. 441 







This access may consist of a new opening or an extension of a cavity, 
or at times the cavity and canal may simply be made continuous. 

When a cavity of decay exists the pulpal wall should be per- 
forated and a large bud bur should be used to cut away the dentin 
overhanging the pulp cavity. It is usually necessary to extend the 



THE EXTIRPATION OF THE PULP 



411 



cavity in the central occlusal direction, so as to permit direct access to 
each canal (Figs. 434 to 440). 

When a tooth crown would be irremediably weakened by such a 
course, a slight indirectness is permissible when flexible cleansers can be 
used instead of drills. This leaving of tooth structure should be done 
with judgment. The canals must be cleansed. In cavity approaches the 
outer wall of the pulp cavity should be cut away to permit an obtuse- 
angled approach rather than a right-angled one (Figs. 439, 441, A). 
All pulp cavity corners should be burred to a shape that obviates reten- 
tion of pulp debris, the subsequent decomposition of which would lead 
to discoloration. The opening shown in Fig. 437 is faulty for this reason, 
and is better if extended more toward the incisal edge, making an oblong 
opening with rounded ends. 



Fig. 442 






\ 



i 



Kerr or Downie broaches. Various finer sizea of these broaches and reamers may be had. 
They should have accurate taper. 



In sound teeth the entrance to the canal is made with a small spear 
drill, after the enamel has had a " spot" made in its surface with a sharp 
dentate bur. This centres the spear drill and prevents its slipping about. 
After it has entered the pulp cavity dentate burs are used to enlarge 
the opening to the desired size and shape. A sawing motion creates 
more rapid clearance and cutting of tooth tissue. 

One should not always suppose that the spear drill will drop into an 
appreciable pulp cavity. The careless driving of a drill into a tooth may 
cause a perforation. Secondary dentin or a large nodule and, in pre- 
viously treated teeth, zinc phosphate may occupy the pulp chamber. 
Therefore, when doubt arises, open well that portion of tooth or filling 



412 



TREATMENT AND FILLING OF ROOT CANALS 



which has been drilled through and note the conditions, then go ahead 
carefully. In opening a located pulp chamber with burs a bud bur is 
very useful, but all burs once placed through the drill hole and into the 
pulp chamber must be used laterally or the heel of the bur used with an 
outward sweep toward the occlusal aspect for the sake of safety. 

The canal (or canals) is now to be explored, and if of operable size a 
Donaldson cleanser or barbed broach is passed to the canal apex, twisted 
so as to engage its teeth with the pulp substance, and the pulp extirpated. 



Fig. 443 



Fig. 44G 



Fig. 447 



Fig. 444 Fig. 445 



I 



i 






» 






Dr. Donaldson's pulp-canal cleansers. 



Dr. Donaldson's spring-tempered nerve bristles. 



If there be any difficulty in finding the canals after this preparation, 
by reason of the broach catching on the edge of the orifice, the mouth 
of the canal should be made continuous with the wall of the pulp chamber 
by means of a small bud bur. The wall then leads the broach into the 
root lumen. 



THE EXTIRPATION OF THE PULP 413 

In single-rooted teeth with finer apices a fine Kerr engine root reamer 
(Fig. 442) may be passed by hand to the apical portion of the root and 
gently rotated. It is then mounted in the hand piece, passed gently 
to the apex, slightly withdrawn, and then operated by engine power. 
It is pressed lightly laterally to enlarge the canal slightly. The next 
larger size is then used in like manner, and finally the larger admissible 
sizes. This gives a beautifully tapered canal form useful in canal filling 
and for the adaptation of dowels. The pulp is simultaneously removed, 
generally being churned out of the root, and danger of false openings 
is avoided. A final exploration and apical scraping may be given with 
a fine Donaldson cleanser (Figs. 443 to 446) and the pulp cavity corners 
rounded out with burs. 

This technique is only admissible in cases of openings in line with the 
pulp axis. Those almost in such line may have the flexible sizes of Ken- 
reamers so used, all apexward pressing and reaming to be done by hand 
at first. When general anesthesia is employed it is better to open 
roughly, then pass a fine Donaldson cleanser, which has been previously 
dipped in carbolic acid and laid aside in readiness, to the apex of the 
root canal. It is given a few turns to engage the pulp, and the latter is 
lifted away. The other work is to be done upon return to consciousness. 

As the Xerr broaches and reamers are made of a variety of forms, 
it should be stated that only those which have a gradual taper from 
point to shank can be relied upon to satisfactorily carry out this tech- 
nique. In these the successive sizes follow one another without danger 
of perforation of the canal walls. 

It is sometimes better to drive a fine hand Kerr broach to the canal 
apex, and, if the engine broach be not permissible, to continue with the 
different sizes of hand broaches. One soon obtains a familiarity with the 
canal curve and size when working with the hand, which gives confidence 
and safety when later working with engine power. 

In molar teeth and upper first bicuspids, after the pulp chamber has 
been prepared, the canals are to be located with a fine smooth broach 
or a Kerr broach. The finest root reamer is then used by hand and 
gently twisted and forced apexward into each canal in turn. The next 
smaller is then used. As these canals are normally somewhat curved, 
only flexible forms should be used unless the larger size follows readily 
the rather curved canal made by the previous one. Following this, 
Donaldson cleansers are operated by hand to scrape the sides and 
inequalities of the somewhat flattened canals which the reamers have 
not reached (Figs. 448 to 451). When the finest Kerr reamer does not 
explore the canal properly, owing to constrictions, a drop of 50 per cent, 
sulfuric or pure lactic acid in water is introduced into the canal and 
a smooth, fine, spring-tempered Swiss broach is used to gently enlarge 
it by drawing it back and forth in the canal. Then a fine Donaldson 
cleanser is to be used in the same manner; later the larger sizes are 



414 



TREATMENT AND FILLING OF ROOT CANALS 



used. If feasible, the Kerr reamers may now be used, when direct 
access is had. If the access be indirect the Donaldson cleansers only 
should be used. 

Some operators prefer the use of the alloy kalium-natrium, used on 
the broach as a means of facilitating the opening of the canals. If acid 
be used it should be neutralized with sodium bicarbonate or sodium 



Fig. 448 



Fig. 449 





Fig. 450 



Fig. 451 





dioxid. The improved Gates-Glidden drill (Fig. 452) has some use in 
the enlargement of canals the lumen of which has been determined by 
the above methods. They should not be used for the preliminary 
opening of fine canals, as they tend to form false channels in the side of 
the canals which constantly catch even fine bristles and may render a 
canal into a form even less advantageous than that it already possesses. 
The canal filament of pulps in molars and upper first bicuspids may be 



THE EXTIRPATION OF THE PULP 415 

lifted away with barbed broaches or cleansers if the canals are large, 
but it is ordinarily a waste of time to attempt it in the finer canals, as 
the other work must be done in the apical regions. 

This technique is, as a rule, best carried out under rubber dam, to 
prevent the septic contamination of canals by entrance of infected saliva; 
but if this be impossible it is wise to sterilize the mouth and napkin it, 
and to place a drop of caibolic acid or formocresol in the canals and con- 
tinue the work under antiseptic precautions. 

It is wise to have the patient first brush the teeth, using soap or a 
tooth paste or powder. After application of the dam or napkin the 
cavity is cleansed of the debris of decay 
if any be present. Then the cavity is to fig. 452 

be wiped out with phenol-camphor. Next 
the application of cocain, etc., is made. 
Before entering the pulp chamber or just 
after, a drop of formocresol is to be 
placed on the field of operation and a 
clean bur used to enter the pulp cavity. 
The debris is removed, the canals located, Improved Gates _ Glidden ncrve _ canal 
and a fresh drop of formocresol placed drill for engine work. 

before continuing with the canal work. 

As the napkins become wet they may be removed, the cavity douched 
with a jet of warm water, the patient rested for a moment, and then the 
napkins are reapplied, the cavity dried, and the operation repeated. 
The napkins may be renewed without disturbing the treatment, but it is 
often desirable to wash out the debris, and the rest is often agreeable 
to the patient. 

The scraping of the canals removes the possible remnants of pulp 
tissue, odontoblasts, etc., adhering to the dentin walls, and also a part 
of the wall with the large ends of the fibrils. All these are decomposable 
media, may become septic, and are wisely removed. 

The final removal of all pulp debris, coagulated blood, etc., is best 
done with a fine Donaldson cleanser moved to and fro in the canal with 
one hand, while with the other a stream of warm water is gently intro- 
duced by means of a Moffat syringe. A large cottonoid roll or a napkin 
may be held by the patient or assistant to absorb the excess of moisture 
when the rubber dam is in position. 

The carrying out of canal treatment involves a knowledge of the 
topographical anatomy of the teeth and their pulp canals. As an aid 
to this Figs. 453, 454, and 455 are introduced, showing the normal 
outlines of the teeth and their pulp chambers. Fig. 455 shows the 
appearance and locations of the pulp canal openings at their coronal 
ends. It is to be borne in mind that the roots are not always normal in 
shape, as shown in Figs. 456 to 489, and that various degrees of lack of 
development or resorption may cause the root canals to be unusually 



416 TREATMENT AND FILLING OF ROOT CANALS 



DESCRIPTION OF FIGS. 453, 454 AND 455 

Fig. 453.— Fig. 3 gives in contrast a sectional view of deciduous and permanent upper teeth 
divided through their lateral diameters. 

Fig. 4, a sectional view of the corresponding lower teeth divided through their antero-posterior 
diameters, a, b, c represent, respectively, the deciduous and permanent front incisors in con- 
trast: d, e,f, the lateral incisors; g, h, i, the canines; k, deciduous molars, upper and lower; and 
I, to, the successors to the deciduous molars, the bicuspids ; n, o represent permanent molars. 
c,f, i, m, o have dotted lines indicating the thickness of enamel removed by wear, atrophy of the 
cementum, and reduction in the size of the pulp due to progressive calcification, these changes 
being incident to old age. 

Fig. 454 represents in Fig. 1, letters a to h and a tort., the longitudinal or vertical sections of 
the sixteen upper teeth, showing the labio-palatal diameter of the pulp chamber and canal in 
crown and roots, the section of the molars being through the anterior buccal and palatal roots, 
while the bicuspids d e and d_e illustrate the result of such a compression of the root as to 
divide the pulp chamber into two canals— a condition which so frequently exists in these flattened 
roots. The double-lettered series, d d to k k and d d to k k , represent in the molars a section 
through the posterior buccal and the palatal roots, from which is quite readily recognized the 
slightly greater lateral diameter of the pulp chamber in the crown and the larger canal in the poste- 
rior buccal root over that in the anterior buccal root, while the bicuspids lettered eedd and ddee 
illustrate a modified pulp chamber and canal, with bifurcation of the root in one, these being cut 
through a different axis or plane from the single-lettered series. 

Fig. 2, letters a to A and a_ to h, represent the sixteen lower teeth with the section through 
their long diameters, as in the upper series. These incisors illustrate the compressed or flat- 
tened condition of their roots in contrast with the cylindrical character of the roots of the upper 
incisors, while the bicuspids d e and d_e illustrate the singleness of their pulp chamber and the 
cylindrical condition of their roots as in contrast with the flattened or compressed condition of 
the roots of the upper bicuspids. The molars -/, g, k and f, g, k represent sections through the 
anterior root, illustrating its compressed condition and divided pulp chamber in the first and 
second molar, and a somewhat flattened one in the anterior root of the third molar ; //, g g ,kk 
and //, g g, k k represent the single and cylindrical pulp chamber in the posterior root of the 
lower molars, while bb, cc and aa,bb represent the incisors and canines of the same series, with 
modified pulp chambers arising from modified development. 

Fig. 455.— Fig. l.from a to k and a to kj represents the upper teeth, with transverse or horizon- 
tal section through the base of the pulp chamber in the crown, viewing the entrance to the canals 
of the several roots, while the same letters in Fig. 2 represent the lower series in the same 
manner. 

Fig. 3 represents the upper teeth, with the transverse or horizontal section made below the 
largest diameter of the pulp chamber and through the canals after they have diverged from the 
central chamber, but before the roots into which they run have in the molars bifurcated. 

Fig. 4 in like manner represents the lower series, well illustrating the flattened or compressed 
condition of the canal in anterior roots of the molars and the division of the chamber, as is fre- 
quently found in the roots of the lower incisors. 

The letters a a, b b, c c, d d,ff, d_d and e e (Fig. 3) represent the relative shapes, whether circu- 
lar, oval, or flattened, of the pulp canal in the roots of the upper central and lateral incisors, 
the canines, the first and second bicuspids, and the first, second, and third molars, while the 
same letters in Fig. 4 represent the relative shapes of the pulp canal in similar teeth in the 
lower series. 

1 These figures are taken from v. Carabelli's Anatomie des Mundts. 



Fig. 453 







27 




(417 3 



Fig. 454 




(418) 



THE EXTIRPATION OF THE PULP 



419 



Fig. 455 



A 







pfi 





if 




,{ f 




s 



^ 



0" 



so 



-5\ 




7.v 






,«' 




420 



TREATMENT AND FILLING OF ROOT CANALS 



open or short with the treatment complicated by the presence of vital 
tissue at the root ends. In a general way it may be stated that much 



Fig. 456 




Fig. 462 




Fig. 457 



Fig. 458 




Upper lateral incisors. (Ottolengui.) 
Fig. 459 Fig. 460 



11 




Upper canines. 
Fig. 463 




Fig. 461 



Fig. 464 




Upper first bicuspids 



Fig. 465 



Fig. 466 




b a 

Upper second bicuspid. 




6 a 

Upper first molar. 



resorbed roots, as indicated by the age in deciduous teeth, or largely 
incomplete roots, as indicated by the age in permanent teeth, indicate 



THE EXTIRPATION OF THE PULP 



421 



a pulp capping operation rather than extirpation; in the permanent 
teeth, to permit better root formation. If unavoidable, one must do 
the best possible (see Figs. 432 and 433). 



Fig. 467 



Fig. 468 



Fig. 469 




Upper molar. 

Fig. 470 





Fig. 471 





Upper second molars. 
Fig. 472 




Fig. 473 



Fig. 474 



Fig. 4; 







Upper molars. (Ottolengui.) 
Fig. 476 




Upper third molars. 



In the penetration and enlargement of canals the larger and straighter 
canals may be cleansed thoroughly to the apex, but in very fine and 
tortuous roots (Figs. 456 to 489) the operator is often confronted with 
the option of taking the chances of perforation by forcing further 



422 



TREATMENT AND FILLING OF ROOT CANALS 



entrance or of leaving some doubtful apical portion uncleansed. The 
decision should be that the danger of perforation is the greater evil, and 
agents of a mummifying character should be employed to render any 



Fig. 477 



Fig. 478 



Fig. 479 








Lower incisors and canine. 



Fig. 480 



V) 

Lower first bicuspid. 

Fig. 482 



Fig. 4S3 





Fig. 481 




Lower second bicuspid. 
Fig. 484 




Lower bicuspids 




Lower first molars. 



such filament into a state lessening the danger of subsequent putre- 
faction. 

The writer regards the use of formocresol (equal parts of 37 per cent. 



THE EXTIRPATION OF THE PULP 



423 



aqueous formaldehyd solution and cresol) as especially valuable where 
immediate root filling is not indicated. If the patient be of nervous and 
irritable type this may be diluted to 5 or 10 per cent, formaldehyd 



Fig. 486 



Fig. 487 






Lower first molar. 



Lower first molar, immature. 



strength by the use of cresol or camphophenique without impairing its 
value. Often the full strength may be used on cotton as a temporary 



488 



Fig. 489 






Lower second molar. 



Lower third molar. 



Fig. 490 



dressing. This hardens any remaining pulp and also probably the 
fibrils in the tubules. It also permits the apical tissue to heal and resume 
its normal sensitivity when the pulp has been entirely removed, which 
is of value in determining the extent to 
which pressure may be applied in filling the 
canals. 

In a few cases in which cervical cavities 
obliterate the canal or cause annoying ap- 
proach to it, it is desirable to remedy the 
condition. In such case the canals are 
opened as usual and enlarged, and the cavity 
prepared with suitable retentions for filling. 
The last-used reamer is then to be placed in 
the canal and the filling inserted. The fill- 
ing is then supported by pressure while the 
reamer is slowly twisted to the right and 
withdrawn, leaving a canal through the fill- 
ing. This may be done with amalgam or 
with zinc phosfate if a later removal be 

required. If the root be much weakened, a tapering dowel may be 
cemented through the crown and canal, thus attaching the root to the 
crown more firmlv. 




Method of restoring lost canal 
continuity. The cavity should 
have more retention form than 
shown. 



424 TREATMENT AND FILLING OF ROOT CANALS 



ACCIDENTS IN CANAL OPENING. 

The chief accidents that may occur are the perforation of the root 
wall and the breaking of the instruments used. If the technique laid 
down be carefully followed the danger of perforation is practically elimi- 
nated. In fact, the greatest danger is the penetration and enlargement 
of the apical foramen. To avoid this the Kerr reamers should always 
be passed to the apex of the canal by hand or while the reamer is not 
revolving. It is then withdrawn a trifle and revolved, and one may 
always judge the distance the reamer was withdrawn. Accidents are 
usually the result of thoughtless forward pressure of reamers and drills, 
and care will reduce this to a minimum. Sometimes one must take the 
chances with the Kerr engine reamer. When doubt exists as to canal 
locations, the desiccation of the pulp chamber is of great assistance by 
bringing them into view, and if secondary deposits exist one should 
always use a small bud bur and keep well within the limits of the dentin 
of a root while gently seeking a canal lumen. 

Frequent exploration should follow gentle advances, and, as a rule, 
the canal will be found of fairly normal size just beyond the point of 
constriction. In some cases 50 per cent, sulfuric acid should be 
sealed against the suspected canal and the operation deferred to another 
sitting. 

If a perforation be accidentally made it should be covered as in any 
case of perforation (which see). 

Always one should be able to diagnosticate such an opening, and 
arsenic should never be applied to such. Cases of extensive necrosis have 
occurred from carelessness in this direction. The breakage of broaches 
is largely avoidable through the use of new instruments and by adhering 
to the rule of using the smaller sizes until the canals are sufficiently 
enlarged to permit the use of larger sizes, and, in case of engine reamers, 
of starting the power with the reamer loose in the canal. 

The engine broach seems to be of better temper than the engine 
reamer. 

Accidents of this sort usually occur with barbed instruments of the 
Donaldson cleanser type, especially when used with force. Sulphuric 
acid tends to disintegrate the broach, so that lactic acid is often better 
used with it, or the alloy of sodium and potassium with a smooth broach 
will open the canal so that the cleanser will not bind. If it bind it should 
be grasped with the thumb and finger and given a straight pull. 

While avoidance is far better than the application of the remedy, if 
the accident occur, the broach should be removed if possible. 

If lying loosely in the canal a new cleanser may be passed to one side 
of it and then be pressed against it. It should engage the barb and jig 
it out. 



CASES IN WHICH THE PULP IS DEAD 425 

Cotton wrapped on a small Swiss broach may be pressed down at 
one side of the broken broach and its fibers made to engage its barbs. 

Moving the broach back and forth, while sulfuric acid, sodium 
dioxid, or sodium and potassium is about it, will sometimes loosen it. 
One may sometimes drill to one side of a broken instrument with a Kerr 
engine broach in order to more readily engage it with a barbed instru- 
ment. If very loose a magnetized probe will attract it and draw it 
out. 

If the broach be tightly fixed in the canal, sodium chlorid, tincture of 
iodin, sulfuric acid, aqua regia, or 25 per cent, pyrozone may be sealed 
in, in the hope of chemically disintegrating it. 

The head of a Gates-Glidden drill or Kerr reamer is treated in the 
same manner. 

If any broach be irremovable, iodoform paste or embalming paste 
should be packed over it and sealed in, in order to keep the parts per- 
manently sterile. In a septic case the formocresol treatment should 
precede such root filling (see p. 401). 

For root filling, see p. 456. 



CASES IN WHICH THE PULP IS DEAD 

There are several classes of cases requiring root canal treatment in 
which the pulp is completely necrosed when the patient presents, and in 
all but one of these the pulp is in a putrefactive condition. Therefore 
the consideration of the treatment may be taken up under the following 
headings: 

1. Cases in which the pulp is in a state of dry gangrene. 

2. Cases in which the pulp is in a state of moist gangrene but no 
evidence of acute pericementitis is present. 

3. Cases in which the pulp is in a state of moist gangrene and subacute 
or acute septic pericementitis is present. 

4. Cases in which the pulp is in a state of moist gangrene and a 
fistula upon the gum or other part is evidence that there has been an 
acute abscess which has passed into the chronic or discharged state. 

Dry Gangrene. — By dry gangrene of the pulp is meant its total death 
under aseptic conditions, and the absorption of its moisture, leaving a 
tough shrivelled mass (Fig. 491). This condition is very rare as a spon- 
taneous occurrence, but no doubt has been frequently induced by the 
application to pulp stumps of mummifying preparations containing 
paraformaldehyd, alum, tannin, or zinc chlorid; indeed, this is the 
intent of the so-called mummifying pastes. The conditions favorable 
are: (1) Pulp death from some aseptic cause, such as the hyperemia 
resulting from a blow on a sound tooth. (2) The constriction of an apical 
foramen, as by hypercementosis, the result of thread biting or other 



426 



TREATMENT AND FILLING OF ROOT CANALS 



mild irritation of the pericementum. (3) The exhaustion of the pulp due 
to secondary dentin, which may protect it from subsequent infection. 
(4) The capping of the pulp with agents having a mummifying and also 
antiseptic action (which includes such treatment of pulp stumps). 
The former practice of using zinc oxychlorid and the present use of 
Jodo-Formagen may have such action if the pulp undergoes irritation 
and death in spite of the cap. 

The tooth may have a good color, the dentin will be insensitive, but 
without odor, and there will be no odor or fluid in the pulp canal. The 
final diagnosis can only be made when 
the pulp is found in the shrivelled state. 
This is of very rare occurrence, odor 
almost always being present. 

Treatment. — The tooth should be 
opened and the pulp lifted away under 
the antiseptic influence of a formal- 
dehyd solution. The canals are to be 
opened as in any case of vital pulp. 

Moist Gangrene Without Pericementitis. 
— The death of the pulp through venous 
hyperemia or inflammation leaves it full 
of moisture. If saprophytic organisms 
gain entrance, it undergoes decomposi- 



Pigment. 



Fig. 492 

Sulfur + hemoglobin. 



Fig. 491 





C0 2 . NH 3 ; 
H 2 and H 3 S 



Aromatic and 
fatty prod- 
ucts. 

Ptomains. 



Peptones. 



Dry gangrene of the pulp: PN, pulp nodule; DP, 
shrivelled pulp. (From a specimen of pulp extracted 
intact in this condition.) 



Diagram illustrating the more complete 
decomposition of the pulp at its coronal 
end. 



tion through putrefaction or fermentation into a series of compounds 
simpler in chemical structure than its own proteid compounds. Albu- 
minous substances putrefy with the formation of (1) peptones, and (2) 
ptomains or animal alkaloids, such as putrescin, neuridin, and cadaverin, 
which are stated to be capable of pus formation in vital tissue when free 
from bacteria. Next, nitrogenous bases, leucin, tyrosin, and the amines; 
also organic acids. Next, aromatic products, indol, phenol, cresol, and 
finally hydrogen sulfid, ammonium sulfid, carbon dioxid, and water. 
The end products account for the presence in decomposing pulps of 



CASES IN WHICH THE PULP IS DEAD 



427 



Fig. 493 



malodorous gases and moisture (Fig. 492) . " Fermentation and putre- 
faction can only occur where the fungi concerned live and the extent 
of decomposition is conditioned by the number of fungi." 1 

In its clinical aspect a putrefactive pulp is of 
the yellow color of sloughing tissue with a reason- 
ably tough consistence, less than the normal, 
however, which indicates recent gangrene with 
beginning decomposition. It next passes into a 
jelly-like consistence, and finally into gases and 
water. Naturally the greatest number of fungi 
will have by multiplication invaded that end 
nearest the source of infection, the mouth or 
cavity of decay, while the more consistent portion 
of the pulp will exist at the apex. This is exactly 
what is found clinically in cases seen at the right 
time. Of course, total decomposition into gases 
and water may occur, so that the canal may appear 
empty or nearly so, yet odor can generally be 
found, as even tubular contents decompose and 
the tooth structure is saturated with the end 




Fig. 494 



Fig. 495 



Sector of a cross-section 
from a diseased root: a, 
oementum; b, stratum gran- 
uIosum;c, very narrow and 
finely branched tubules; d, 
penetration of bacteria into 
tubules. X 150. (Miller.) 




1 




Dentin from the root of an ab- 
scessed tooth, showing the penetra- 
tion of cocci to a depth of about 
yo mm. (^o 11 i n -)- *' ie s '^ e a "'' 
bordered upon the canal. X 1000. 
(Miller.) 



Skiagraph of unfilled root 
canals with large mass of fill- 
ing material built in over 
them. (Price.) 



Ziegler. 



428 TREATMENT AND FILLING OF ROOT CANALS 

products (Fig. 493). As the pulp decomposes, the H 2 S combines with 
the NH 3 of proteid origin to form NH 4 HS or (NH 4 ) 2 S, which in turn 
combines with the iron of the hemoglobin, forming Fe 2 S, which darkens 
the tissue. Partial gangrene, the apical portion of a pulp being vital, 
is sometimes seen, and sometimes one canal filament will undergo 
decomposition and even produce an abscess, while another or two 
other filaments remain vital. 

As these gangrenous pulps often produce apical abscesses, they must 
contain pyogenic organisms; still, abscess and ulceration in which the 
pulp body undergoes putrefactive decomposition, with formation of 
pus, is not necessarily gangrene, but rather a necrobiotic process. 

Arkovy found that pulps infected with the Bacillus gangrense pulpse 
in pure culture would undergo total gangrene without suppuration, 
while when infected with mixed cultures or even pleomorphic forms of 
the Bacillus gangrama© pulpse chronic pulpitis was produced. If the 
mixed culture contains pyogenic bacteria it is plain that the chronic 
pulpitis may be suppurative. 

Gangrenous pulps do not necessarily produce abscesses at once, but 
often clinical history shows that a year or two, or even more, may elapse, 
though as short a time as two or three weeks has sometimes been suffi- 
cient. In one case of a boy, aged ten years, the time between a capping 
of a bleeding pulp with Jodo-Formagen and the presence of a fistula 
upon the gum was but two weeks. It was, however, in a temporary 
first molar, and the cement covering the cap was found to be loose. 

The forcing of gangrenous pulp tissue by instrumentation into apical 
tissue generally results in an abscess, even when extraneous bacteria 
are presumably not introduced. 

The irritating substances in a decomposing pulp are presumably the 
bacteria, the ptomains, and the expanding gases. 

Many decomposed pulps produce no pain, but in these cases the gases 
may escape via dentinal tubules and leaks about fillings (Fig. 495). 

Clinically, putrefactive pulps may be found in sound teeth, in filled 
teeth, and in teeth the pulp cavities of which are open to the oral fluids 
either actually or through the medium of open tubules in the dentin 
over them, or in apical portions of poorly cleansed or partly filled canals. 
A cotton dressing having a bad odor, or an apparently empty apical 
portion of canal or a leaky gutta-percha canal filling associated with a 
bad odor, even though the pulp has been successfully removed, have a 
similar pathology. There is little difference in principle between putre- 
factive serum or tubule contents and a putrefactive pulp. Any of 
these may cause abscess or remain quiescent. 

Symptomatology. — The symptoms are opacity of the tooth evident 
to the eye or noted by transmitted light, discoloration of varying 
degrees, odor and discoloration of the dentin in a cavity. 

There is a lack of response to cutting, thermal and electric tests. 



CASES IN WHICH THE PULP IS DEAD 429 

Sometimes a bad taste due to leakage is present. Looseness, tenderness 
to percussion, incipient and acute abscess, and a chronic fistula are 
evidences of pericemental irritation. 

Pain to heat, while usually indicative of pulp irritation, also sometimes 
occurs, and is explainable upon the same theory of the expansion of 
gases against vital tissue — in this case the apical tissue. These symp-- 
toms are all explained by the pathology of the condition. 

Treatment. — The pulp being presumably infected, all quiescent 
gangrenous pulps or putrefactive conditions under any conditions, 
discovered indicate a similar treatment, namely, first disinfection to 
remove or kill bacteria which might cause an abscess and at the same 
time to destroy the chemical nature of the gases and ptomains. After 
this the canals are to be thoroughly opened. 

Three substances are preeminent in this direction — (1) formaldehyd, 
(2) nascent oxygen, (3) iodin or its derivatives. 

At the present writing no substance equals formaldehyd, because of 
its rapid diffusion through all canals, tubules, and even abscess tracts. 

The first and best treatment consists in opening the pulp cavity and 
gently removing the bulk of decomposed pulp from the pulp chamber 
and canals, care being employed to avoid forcing any putrid material 
into the apical tissue by broaching or plunging of the bur. Also, no 
bacteria should be introduced from outside. The opening should not 
be too freely made, and should be funnelled or countersunk outwardly 
to secure the seal against being plunged into the pulp cavity in masti- 
cation (Fig. 496). 

This being done, the canals are dried with cotton and hot air, and a 
small pellet of cotton saturated with formocresol or 10 per cent, aqueous 
formaldehyd solution is to be placed in the pulp chamber. Any that 
has come in contact with the orifice should be removed with alcohol. 
The orifice is then dried and a small piece of dry spunk placed over 
the application, but not so as to interfere with the seal. Quick-setting, 
adhesive, hydraulic cement is now flowed into the orifice, air bubbles 
being avoided by flowing it in with an instrument. A bit of paraform 
accomplishes the same purpose as the solution, namely, the liberation 
of formaldehyd gas. 

When opportunity for self-relief seems proper, as when the operator 
is leaving his practice for a short time, or may otherwise be inaccessible, 
hot temporary stopping may be used and the patient instructed as to 
the proper procedure to obtain relief. An ordinary pin crooked at the 
point by striking it across any hard surface will serve to pick out the 
stopping and cotton. In all cases tight coverings must be made, as 
the object is to concentrate the action of the formaldehyd gas upon 
the canal and tubular contents. 

In some cavities it is well to make the covering first, as done for arsenic 
(see Fig. 430), and to seal the dressing in with a further addition of 



430 



TREATMENT AND FILLING OF ROOT CANALS 



cement or temporary stopping. The latter does not permit mastication 
like the former. 

If there be a broad cavity extending beneath the gum, it is well to press 
the gum away with cotton pellets, then to form the cavity and open the 
canal orifices. Then a retention at the cervical portion of the cavity 
should be made, even if it be necessary to drill a series of pits along it 
with a No. 1 bur. Spunk is now placed over the pulp canals and 
quick-setting amalgam is to be permanently built in at this part of the 
cavity. When set the spunk is withdrawn, formocresol in cotton is 
inserted instead of the spunk, and the covering completed with cement. 
The amalgam is finished as far as practicable at the one sitting and the 
case dismissed. At future sittings rubber dam may be applied and the 
canal work done (Fig. 497). 



Fig. 496 



Fig. 497 





a, cotton and formocresol; b, spunk, 
c, cement. 



Cervical wall built up with amalgam to permit 
canal sterilization and treatment. 



Formocresol consists of equal parts of 37 per cent, aqueous formal- 
dehyd solution and cresol, which combine well. 

According to Buckley, the formaldehyd not only acts as a germicide, 
but combines with the ammonia of ammonium sulfid to form uro- 
tropin and with hydrogen sulfid to form methyl alcohol and sulfur. 
The cresol is supposed to act upon the fatty compounds, changing them 
into a compound resembling lysol. Thus, antiseptic substances are 
formed from poisonous ones. Formaldehyd is so efficacious in the 
writer's hands that it has displaced other methods in his practice. All 
other methods of disinfection produce results less certain than those 
produced by it and are more cumbersome, therefore they will be here 
dispensed with. While this is true for a great majority of the cases, occa- 
sionally a patient is met with whose tissues do not tolerate formalde- 
hyd well. Formocresol then should be reduced to a 5 per cent, solution 
with cresol or phenol-camphor, and in some cases abandoned for more 
sedative antiseptic remedies, such as eugenol or phenol-camphor with 
menthol. 

This first dressing may be left for from twenty-four hours to a week, 
or longer if the patient is comfortable. 



CASES IN WHICH THE PULP IS DEAD 431 

At the second sitting the rubber dam is to be applied and the canal 
opening thoroughly made under formocresol influence, just as though 
the pulps were vital, the technique differing in no respect. A second 
dressing is introduced into the canals. Whether this shall carry the full 
strength formocresol or it shall be modified by the addition of cresol 
or phenol-camphor depends upon the history of any irritation or perfect 
comfort as a result of the first application. The object of a second 
dressing is to determine whether the odor (gases) has been discharged 
from the tubules. When the dressing has absence of putrefactive odor, 
no pus can be detected, and the patient is comfortable, the canal is ready 
for filling. Less than this result is too soon, and delay beyond this is a 
loss of time. 

When one pulp filament is gangrenous and another vital, the treat- 
ment is the same, it being the writer's experience that formocresol 
loosely placed is not incompatible with ulcerated pulps, and, indeed, is 
an excellent dressing for suppurative pulps when modified to a 3 to 5 
per cent, strength. Later, the vital portion is appropriately removed. 

When apical pericementitis of a subacute nature is present on a 
filled tooth, as when a tooth shows some looseness and tenderness, with 
some injection of the gum, all faulty root canal fillings should be 
removed with barbed broaches, cleansers, or root reamers, and the case 
is then resolved into one of moist gangrene and treated accordingly. 

If a cotton root filling be found it sometimes allows the broach to 
tear loose. In such case a Kerr broach is driven into it to create a 
central opening, after which the fibers become engaged by the barbed 
broach. 

Eucalyptol may be used to soften gutta-percha root canal fillings, 
and at times the smallest Kerr or Downie broach is to be bibevelled at 
its end and used as a drill cutting its way. Oxychlorid and other 
cement fillings may have 50 per cent, sulfuric acid or strong ammonia 
water applied to them to assist in breaking up the bond of the cement 
by chemically destroying either the zinc oxid or the acid. The drill 
will tamp the fluid into the cement and cut the cement at the same 
time. 

All root fillings of cement nature are apt to be faulty when used as 
such, because the air in the canal prevents ingress, though it may appear 
to be well filled. This fact is of importance in diagnosis in filled teeth, 
giving evidence of chronic pericementitis, i. e., there is probably an 
unfilled portion of root canal containing putrefied pulp or serum. 

It is a weakness of good operators, if not of all, to think that their 
individual canal fillings are perfectly made. The writer was once asso- 
ciated with a most conscientious man, and possesses a gutta-percha 
canal filling of his in a molar now successful for twenty years. On one 
occasion he declared that he had filled perfectly a canal of an upper 
second bicuspid because the material had been felt by the patient as it 



432 TREATMENT AND FILLING OF ROOT CANALS 

reached the apex. Two weeks later the tooth was extracted, though 
comfortable, for orthodontic purposes. Its well-opened canal was empty 
for a quarter of an inch at the apex. 

To remove pins from roots a bibevelled Kerr broach may be driven 
into the cement or dentin about it and the drifts united. The pin may 
often be forced to one side and then jigged loose. If there be sufficient 
pin extending above the face of the root a "pin puller" may be used. 
If the pin cannot be loosened it must be drilled out bodily. A sharp 
round bur should be used to countersink the end of the pin, and then 
by the aid of oil it is cut into shavings. Frequent desiccation and exami- 
nation to observe the presence of a metal remnant is necessary to avoid 
the accident of perforation. 



DENTO-ALVEOLAR ABSCESS 

The term dento-alveolar abscess is a comprehensive one, meant to 
include all those cases of abscess having a beginning in the pericementum 
of a tooth and extending into the alveolar process or maxillary bone, 
and which have their origin in septic matter located in or introduced by 
way of the root canal of a tooth. It includes the anatomically specialized 
abscesses of such origin, e. g., apical abscess, beginning at the apex of 
the tooth, or lateral abscess, beginning in a perforation. The description 
of the pathology of apical abscess serves for the other. It may be, but 
should not be, made to include pericemental abscess due to pyorrhea 
alveolaris. (See Chapter XV.) 

Causes. — An apical abscess is a septic and suppurative pericementitis 
beginning in the pericementum at the apex of a tooth (the apical tissue) . 
The pyogenic organisms, the Diplococcus pneumoniae, the Staphylo- 
coccus pyogenes aureus and albus, and the Streptococcus pyogenes^ 
are the probable causes of the infection, as examination has shown 
(Schrier). These may exist in a gangrenous pulp, be introduced upon 
instruments uncleansed from a previous infection, or contaminated by 
contact with saliva or unclean hands at the time of operation, or the 
infection may have crept in by way of leaks in cavity or canal fillings. 
In apparently sound teeth the infection either enters by way of cracks 
or open tubules at the necks of teeth or beneath such cracks or in a pyor- 
rhetic case through the apical foramen by way of the epithelial debris of 
the sheath of Hertwig constituting the resting cells of the peridental 
membrane. Entrance by way of the blood is a more remote possibility. 
Whatever be the avenue of entrance, infection occurs and produces the 
phenomena of suppurative inflammation (Fig. 498) . There is arterial 
hyperemia followed by a venous hyperemia due to a collection of leuko- 
cytes along the walls of the small veins; emigration of leukocytes and 
exudation of lymph into the perivascular tissue occurs. In the area of 



DENTO-ALVEOLAR ABSCESS 



433 



acute and active inflammation stasis occurs. The exudate, leukocytes, 
and tissue cells are liquefied by the peptonizing action of the bacterial 
ferments into pus. Coincidently these processes produce much swelling, 
which causes the pushing of the tooth from its socket, which in turn 
causes its overocclusion with its antagonists, and the mechanical irrita- 
tion from this becomes an added cause of irritation. The inflamma- 
tory process spreads out from the central focus of pus formation, there 
being around the pus a zone of active inflammation or stasis; about 
this one of a lesser degree of inflammation, also full of leukocytes; about 
this an area of arterial hyperemia or the first stage of inflammation, 
and around this normal tissue. These areas are not sharply defined, 
but merge into one another (Fig. 498, A, D, E, F). 



Fig. 498 




Showing the morbid anatomy of septic apical pericementitis (acute): A, pus; B, area of dying 
leukocytes; C, septic matter in root canal; D, excavation of process (osteomyelitis; area of lesser 
inflammation): E, swollen periosteum and gum, hyperemic or normal; F, alveolar bone in astateof 
hyperemia; G, pericementum at edge of necrosis. 



In this way the contiguous area of the alveolar bone and the soft 
tissues of the face become involved in the process, being discolored and 
tumefied in proportion to the extent of the pus formation and the 
inflammatory reaction thereto. 

From a clinical viewpoint the abscess is incipient when inflammation 
of the apical tissue next to the foramen is profound and pus formation 
has just begun (Fig. 49S). 

The apical abscess is considered to be in the first stage while the 
pus is still in the apical tissue, in the second stage while the pus 
28 



434 



TREATMENT AND FILLING OF ROOT CANALS 



is involving the bone marrow in the alveolar bone (Fig. 499), in the 
third stage when the pus is in the soft tissues overlying the bone 
(Fig. 500), and as chronic when the pus has discharged, forming a fistulous 



Fig. 499 



Fig. 500 





Acute abscess in second stage. Tooth 
opened at b for treatment, making a blind 
(Black.) 



Acute aveolar abscess of a lower incisor in 
the third stage, with pus cavity between the 
bone and the periosteum: a, pus cavity in 
the bone; 6, pus between the periosteum 
and bone; c, lip; d, tooth; e, tongue. (Black.) 



Fig. 501 



Fig. 502 





Abscess upon lower third molar, showing 
the usual paths of pus exit, A and B. 



Abscess upon palatal root of an upper molar discharging 
at the neck of the tooth. 



tract or sinus (Fig. 501), or has discharged via the canal (Fig. 499). 
These areas are the ones successively involved, and as the pus pene- 
trates them the character of the involvement of the superjacent struc- 



DEN TO- ALVEOLAR ABSCESS 



435 



tures changes to the more severe form. Thus with pus formation 
incipient there is normal tissue at the gum surface (Fig. 498) . With more 
advanced pus formation in the apical tissue the normal gum surface 
changes to hyperemic tissue, then inflamed tissue, then pus-containing 




Fig. 504 




Dento-alveolar abscess at the root of 
a superior incisor, discharging into the 
nose: a, large abscess cavity in the 
bone; b. mouth of fistula on the floor of 
nostril; c, lip; d, tooth. (Black.) 

Fig. 505 



Dento-alveolar abscess at the root of an 
upper molar discharging into the antrum of 
Highmorc: a, abscess cavity in the bone; b, 
mouth of fistula on the floor of the antrum; c, 
pus in the antral cavity. (Black.) • 

Fig. 506 




Chronic abscess of upper incisor, showing tendency 
of pus to progressively destroy pericementum, owing 
to the influence of gravity. 




Chronic abscess upon lower tooth, 
showing tendency of pus to sink into the 
substance of the lower maxilla, owing to 
the influence of gravity. 



tissue tumefied according to the amount and progress of the pus toward 
the surface (Fig. 500). The same theory applies to the swelling of the 
face. 

While the abscess usually discharges through the alveolar plate and gum 
tissue either buccally or lingually (Figs. 501 and 507), it does not always 



43G 



TREATMENT AND FILLING OF ROOT CANALS 



do so, but may discharge through the tissues of the face (Figs. 509 to 
514), or into the antrum (Fig. 504), nasal cavity (Fig. 503), the floor 
of the mouth or pharynx (Fig. 513), or even dissect its way between the 
muscles of the neck and discharge at the clavicle. 



Fig. 507 



Fig. 508 





Chronic apical abscess discharging through the hard 
palate and threatening to discharge labially. 



Chronic abscess, showing denudation 
of apex of root (a to b), with deposits of 
calculi (a) upon cementum. 



Sometimes it has a partial discharge by way of the root canal, either 
naturally or as the result of the abortion of it through the intentional 
opening- of the root canal. Sometimes it dissects its way along the 
pericemental tract and discharges at the neck of the teeth (Figs. 501 
and 502). An abscess on a root perforation near the gingival margin 



Fig. 509 



Fig. 510 





Scar caused by alveolar abscess discharging 
on the face. (Black.) 



Operation for the remedy of scar on the face 
caused by alveolar abscess. (Black.) 



is very prone to do this, although it may discharge through the gum over 
the perforation. More than is often supposed the pus formation is 
subacute and the pyogenic bacteria inactive, so that the pus is semi- 
encysted in a fibrous enclosure or sac with organized and thickened 



DENTO-ALVEOLAR ABSCESS 



437 



walls. The abscess may remain in this state for some time or develop 
an acute form (Fig. 515). 

The adjoining teeth usually have more or less pericementitis, and the 
pulps may become hyperemic in consequence and be more responsive 
to thermal changes. In some cases the adjoining teeth are profoundly 
involved. 

There is unquestionably a great difference in the severity of abscesses 
in different individuals, some having great tissue reaction and painful 



Fig. 511 



Fig. 512 





Fistula passing down through the body of the lower 
maxilla. (Black.) 

Fig. 513 



Chronic dento-alveolar abscess 
of the root of the lower incisor, 
with abscess cavity passing 
through the body of the bone and 
discharging on the skin beneath 
the chin: a, very large abscess 
cavity; 6, mouth of the fistula. 
(Black.) 




Abscess with tortuous sinus, opening upon the face: A, 
tissue of cheek; B, floor of mouth; C, abscess tract. 



resistance to pus advance, or length of duration and wide involvement 
of the soft tissues, while others have an abscess reach to the formation 
of a fistula with little or no pain or facial swelling. The average time 
required is from twenty-four hours to three days. The anemic, cachectic, 
and strumous, as well as those having a syphilitic or tuberculous infection 
or history, are more liable to produce abscesses because of their general 
lessened resistance, and their pulps die more readily under conditions 
in which the pulps of others would live. In no case, however, can these 
conditions alone produce abscess. The exciting cause must be present. 



438 



TREATMENT AND FILLING OF ROOT CANALS 



Fig. 514 



When these predisposing conditions exist, however, and abscess super- 
venes, the relatively low resistance of the tissues may permit extensive 
destruction both as the result of the acute and chronic forms. 

There are frequently manifestations of systemic intoxication from 
the toxins formed during the suppuration and absorbed from the 
inflammatory focus. Thus in ordinary acute cases there is some fever, 
often ushered in with a chill or chilliness. The pulse increases in volume 
and tension, is full, hard, and frequent. The tongue is coated, the 
breath fetid, the bowels constipated. The patient is weakened and 

made irritable by pain and the attendant 
loss of sleep and appetite. In the infec- 
tion by Streptococcus pyogenes there is 
danger that these may change into the 
more profound symptoms of septicemia, 
i. e., a soft, frequent pulse, repeated chilis, 
diarrhea, clammy skin, general depression, 
and a disordered nervous system. Also 
in such an infection there is more cellulitis 
and less pus formation. 

Diagnosis. — While the symptoms usually 
indicate a clear diagnosis, this is not 
always the case. A tooth may have a 
perfect color sometimes when examined 
by the transmitted rays of an electric 




Fig. 515 



Chronic dento-alveolar abscess at the 
root of a lower incisor, with a fistula dis- 
charging on the face under the chin: a, 
abscess cavity in the bone; 6, b, b, fistula 
following in the periosteum down to the 
lower margin of the body of the bone and 
discharging on the skin. (Black.) 




Small abscess upon roots of an upper molar. 



mouth lamp; usually, however, it has at least an opaque appearance. 
Of two pulpless teeth surrounded by a zone of inflammation, the most 
tender is the one affected, although both may be involved at once. 

A pericemental abscess due to pyorrhea alveolaris is located laterally, 
as a rule, and while it involves swelling of the gum, usually has not 
much facial involvement. Usually also it is connected with a pyorrhea 
pocket. 

An abscess may be found in connection with a broken root or carious 
bone. 



DENTO-ALVEOLAR ABSCESS 439 

This is usually of the chronic variety in case of necrosed or carious 
bone, with one or more fistulse leading to the diseased area. 

A sinus usually leads from the occlusal direction to a broken root. 
If the gum has healed in this direction the abscess, if not acute, may 
be found with a sinus upon the side of the gum. An impacted tooth 
or odontome may have an abscess associated with it. If chronic the 
probe leads, as a rule, to enamel or the peculiar body. A cyst may be 
associated with a sinus. 

An abscess sometimes forms beneath the flap of gum overlying 
a third molar. This begins as an ulceration of the under side of the 
flap, but the pus burrows between the tooth and the gum, and when well 
confined may develop laterally, causing the formation and at least 
partial retention of a quantity of pus in the tissues of the cheek. This 
condition more nearly simulates the lateral abscess associated with a 
pyorrhea pocket, and as by extension it sometimes involves the tonsil 
the case may be mistaken for an amygdalitis. 

The direction pus may take is often determined by gravity, but the 
resistance of certain tissues may cause the pus to seek the easiest path. 
Thus, by discharging into the antrum it goes rather counter to gravity. 
In such cases as discharge into the antrum there is liable to be a collec- 
tion of pus in that cavity which may cause destruction of the mucous 
membrane and bone. This condition is known as empyema of the 
antrum. The sudden subsidence of an acute abscess upon a tooth 
located beneath the antrum should create a suspicion of discharge into 
that sinus. If a fine probe can be passed an unusual length into a root 
canal it indicates this form of sinus involvement. 

Upon a sound tooth the evidences of pulp vitality or death should 
be observed, i. e., the pink translucency or the opacity to light trans- 
mitted by an electric mouth mirror, or the thermal tests of great heat 
or cold applied. 

If the tooth be filled, or the dentin uncovered at any point, the 
interrupted electric current or the galvanic current, with the anode 
applied to the tooth, the cathode at the hand, produces a slight shock. 
In case of exposed dentin, dryness may interfere with the test. When 
a sinus is present a soft silver probe may often be passed toward the 
tooth affected. 

As a rule, a sinus lies distally to the affected tooth. Taken in con- 
junction with the symptoms, the history, appearance, or reactions to 
tests afford a certain diagnosis. If a tooth be opened upon suspicion, 
evidence of vital dentin (sensitivity) should be carefully observed, as 
the drill is made to penetrate it. A timid patient will often uninten- 
tionally confuse pericemental tenderness with the pain of sensitive 
dentin. 

In very doubtful cases, as when molars have deep amalgam fillings, 
or pins have been placed in root canals, or gold crowns cover the natural 



440 TREATMENT AND FILLING OF ROOT CANALS 

crown, one should obtain a radiograph or else perforate the filling or 
crowns carefully and observe the conditions of sensitivity, odor, etc. 
In teeth filled having a history of canal fillings it is wise to suspect an 
imperfect or unattempted root filling. 

Prognosis. — In a vast majority of cases the prognosis is good if the 
patient submit to the necessary therapeutics. If these can be thoroughly 
applied and regeneration of tissue induced the case may be considered 
cured. 

Treatment. — In the initial inflammation and first stage of pus forma- 
tion in an acute abscess the treatment should be abortive. 

This consists of opening the pulp canals by removing any obstruc- 
tions to its connection with the surface of the enamel, whether this be 
enamel, a filling, a root canal filling, etc. The one possible exception is a 
fixed and irremovable crown. 

This must often be done under counterpressure, as the pericementum 
will be responsive to pressure. A thread knotted about the neck of the 
tooth may be gently pulled by the patient as the operator drills, or a bit 
of modelling compound may be moulded over the opposite surfaces of 
several teeth, chilled, and held by the finger of the operator. Holding a 
tooth with the finger and thumb or pressing a tooth firmly in one direction 
will often sufficiently steady it against the drill pressure or shaking. 

The point of access may be through the dentin of a cavity, by partial 
or total removal of a filling and dentin perforation; by perforation of 
the enamel and dentin, or in unusual cases, where no better can be done, 
by perforation of the cementum and dentin at the neck of the tooth. 

The manner of drilling is described on page 411. When the opening 
is made the canal should be washed with an antiseptic, while a barbed 
cleanser is gently passed to and fro until all debris is removed, and if 
possible the apical foramen cleared so that gases and pus may be dis- 
charged via the canal. The presence of blood in the canal is evidence of 
a complete discharge of the abscess contents. This usually gives prompt 
relief after a possible preliminary throbbing. The writer finds it best 
to leave the tooth open in the severe acute cases. 

In order to lessen the irritation of occlusion upon the affected tooth 
a "guard" made of rubber dam should be applied to a slightly distant 
tooth. This consists of a strip of rubber dam about two inches long 
and as wide as the distance from the lingual to the buccal cervix over the 
occlusal face of the selected tooth. This is then folded into a pad the 
width of the occlusal face. A needle threaded with floss silk is then 
passed down through the right proximal corner, back through the right 
distal corner, down through the left distal corner, and back through the 
left proximal corner. This leaves two loops, as shown in Fig. 516. 
These are passed between the teeth mesially and distally of the selected 
tooth; the free ends are pulled, drawing the lingual loop up to the tooth. 
The free ends are now made into a surgeon's knot. This is to be left 



DEN TO- ALVEOLAR ABSCESS 441 

until the tenderness of the abscessed tooth has almost gone. Aconite 
and iodin, equal parts of the tincture, or dental tincture of aconite, 
should be painted upon the gums, a pad of cottonoid placed over it, 
and the patient cautioned not to swallow the saliva. 

Cold antiphlogistics, such as lead water and laudanum or cataplasma 
kaolini, should be applied externally. No hot external applications 
should be used in abscess cases, as they may cause an external fistula 
to be formed. 

The mouth is to be frequently washed with an antiseptic. In simple 
cases with prompt relief this is all that is necessary ; in marked cases the 
reduction of the inflammatory engorgement should be attempted in 
addition. 

Fig. 516 





Rubber dam guard for use in pericementitis: A, roll of dam threaded; B, guard fitted over tooth; 
tooth eliminated to show the manner in which the silk, encircles it. 

Sweedish leeches may be applied to the gum, or a cut or two made 
in the gum over the apex of the tooth will allow free bloodletting and 
drainage of the excess of blood in the pericementum. A hot pedi- 
luvium and a saline cathartic conjoined are useful as counterirritant 
derivatives, and the latter is also depletive, reducing the volume of 
the blood. The hot pediluvium with mustard added and diaphoresis 
conjoined are also useful. Ten grains of Dover's powder in divided 
doses in hot lemonade are given, in part, while the pediluvium is being 
administered, and the patient is later well covered up in bed. 

Quinine in doses of gr. vj is given as a febrifuge and to limit exuda- 
tion, and tincture of aconite, two drops at first and one-half drop 
each half hour, is given until the volume, tension, and frequency of the 
pulse are reduced. 

If syphilis be a complication in these cases, potassium iodid, in 
doses of 10 grains each three hours, is useful as an antagonist of its 
influence and as a nervous sedative. Unless Dover's powder is used, 
morphin sulfate in blondes and morphin bimeconate in brunettes, 
especially those with blue eyes, or any persons with known idio- 
syncrasies to morphin, should be administered in | grain doses repeated 
each hour up to f grains. When great suffering renders it necessary, 
a hypodermic may take its place. When used, a saline cathartic should 
be given the following morning. 

The Second Stage of Acute Apical Abscess. — In this stage the pus is in 
the bone and the infection considered more virulent, i. e., the germs are 



442 TREATMENT AND FILLING OF ROOT CANALS 

especially active. The abortive treatment should first be tried, and if 
free venting of pus is obtained, relief is usually given. If not given the 
case continues to the third stage. If bearable, or the surgical method 
be impracticable, a dental capsicum plaster may be applied to the gum 
or a roasted half-raisin may be applied. Either causes an inflammation 
of the gum, which advances the tissue that much nearer suppuration. 
Thus, it prepares a readily invaded tissue and hastens pointing. 
The contrary effect has sometimes been produced, and is explained 
upon the ground that the increased amount of blood has increased the 
phagocytosis and destruction of bacteria or has stimulated a restoration 
of the circulation, possibly both. Morphin is a useful adjunct when 
the pain is severe. For the purpose of hastening suppuration, calx 
sulphurata, $ grain each hour, is useful. It also sometimes hastens 
resolution. It is proper to denominate this the expectant treatment. 

When tolerable or imperative, the surgical method of venting the 
abscess through an opening in the gum is valuable. The apical region 
is located as nearly as possible by measuring the length of the tooth with 
a probe passed into the canal and over which a small piece of rubber dam 
is slipped as a guide. This is laid over the crown and gum and a tiny drop 
of carbolic acid is placed just above the point of the probe. A vertical 
cut is made in the gum down to the bone and a broad spear drill 
is driven through it into the abscess tract. Whether this shall be 
done under ethyl chlorid refrigeration, cocainization, or short general 
anesthesia, the operator must determine. 

A gradual perforation is useful in some cases. This method, designed 
by Black, consists in gradually escharing and scratching the gum tissue. 
Successive applications of just such carbolic acid as adheres to the point 
only of a sharply serrated plugger are made, followed by slight scratch- 
ing only so that blood shall not be drawn. In this way the bone is 
ultimately reached. 

A fresh drop of acid is applied, the periosteum scraped away slightly, 
and the drill then used. 

A Rollins tubular knife (Fig. 517) has been used with success to remove 
a piece of gum, after which the drill or a fine trephine (Fig. 518) is used. 
Some acute pain may follow this operation, but usually lasts only a 
short time. 

If antiseptics are used to syringe out the abscess cavity, it is better 
to use a mixture of six parts hammamelis (aqueous) and one part 
Listerin as a partial sedative. The use of hydrogen dioxid is often 
very painful, owing to the rapid reaction with the blood present ; and as 
it sometimes also drives the infective material into remote parts without 
disinfecting it, its use in this connection is not without danger, and 
should be avoided. 

If extraction be imperative during the second stage of pus formation, 
it may be performed and removes the exciting cause. The alveolar 



DEN TO- ALVEOLAR ABSCESS 



443 



apex should be sterilized, and if return of sepsis is feared, a tent of 
antiseptic gauze may be inserted for a day only, and should then be 
removed and the cavity resterilized. Then a clot is invited by curetting 
the part. Ordinarily the extraction and free bleeding cures the case. 

If secondary swelling occur, it is easy to remove the clot and then 
treat as above. The consensus of opinion of the best informed of the 
profession is that this procedure is correct. 

The Third Stage of Acute Apical Abscess. — In this stage the pus has 
found its way through or beneath the periosteum on the outside of the 
bone; therefore, its germs are engaged in liquefying the gum tissue or in 
unusual location the mucosa or muscular tissue of the part. Except in 
these cases the gum is tumefied, a hard, circumscribed, inflamed nodule 
indicating pus near the bone, a soft, more generally diffused swelling 
indicating more superficially located pus, while a soft yellow or yellowish- 



Fig. 51 



Fig. 518 



o O 



Fig. 519 





Tubular knives. 



Walker-Younger trephines. 



Rubber cap used as a vacuum cup. 



pink tumefaction indicates pointing. In all these cases the indication 
is for a surgical opening of the gum rather than the opening of the tooth. 
The part should be gently disinfected with hydrogen dioxid on a ball 
of cotton, and a sharp bistoury should be boldly driven to the bone, with 
the cutting edge turned toward the occlusal. The lip or cheek is to be 
drawn well away to avoid injuring the coronoid, buccal, or facial artery. 
A cut about three-quarters of an inch in length is rapidly made by 
sweeping the edge and point downward occlusally. Too deep lancing 
upon the hard palate may injure the posterior palatine artery. 

As this is usually painful, it is better to refrigerate the gum or operate 
under short general anesthesia, e. g., nitrous oxid or the first impres- 
sion of ether. Cocain is only useful in the case of deep-seated pus. 
Next, the abscess tract is to be gently washed out with a diluted ham- 
mamelis solution, preferably warmed. This may be done with the 
abscess syringe (Fig. 521). 



444 



TREATMENT AND FILLING OF ROOT CANALS 



If the abscess has been deep-seated it is well to introduce a fine tent 
of antiseptic gauze through the opening into the abscess tract to pre- 
vent the too rapid healing of the external orifice which is apt to occur, 
owing to the approximation of the lips of the wound produced by cheek 
pressure. This healing permits a second collection of pus. The tent 



Fig. 520 

o 



Fig. 521 






Minim syringe. 



J. N. Farrar's alveolar-abscess syringe. 



should be removed not later than the next day, the abscess tract disin- 
fected again, possibly with a mercuric chlorid solution, and the tent 
replaced. At this time the tooth should be opened and disinfected if 
not tolerable at the first sitting. When this is tolerable the crown 
should be tapped and formocresol sealed in the pulp chamber just before 
the operation of lancing, in order to permit disinfection, and thus limit 



DENTO-ALVEOLAR ABSCESS 445 

pus formation and to save time. Tents in alveoli should never be left 
a long time, as they become septic and may cause necrotic conditions 
of the alveolus. 

The patient should always be cautioned to remove the tent if swelling 
return, as this indicates a stoppage of the vent with collection of pus. 

When diffuse cellulitis with marked febrile disturbance passing into 
the adynamic type is produced, one should fear the infection with 
Streptococcus pyogenes and treat not only locally, but use blood germi- 
cides against a possible septicemia. In these cases there is little pus 
formed compared with the area involved. 

The following is especially useful as a systemic antiseptic stimulant: 

1$ — Hydrargyri bichloridi gr. j 

Tincturae ferri chloridi foj — M. 

Sig. — Twenty drops in water four times a day. 

If the adynamia and other symptoms be progressive, medical cooperation 

should be obtained to divide the responsibility and to afford every 

means possible toward the cure. The extraction of the tooth followed 

by sterilization and curettement of the part, and the use of streptococcus 

antitoxin conjoined with the sustention of the vital powers by nutritious 

predigested food and alcohol is logical. In even ordinarily severe cases 

not of this variety there will be some fever due to the toxin absorbed, 

and the pain, and loss of sleep and appetite will cause physical debility. 

For this there is nothing better than the following, as tonic, antiseptic, 

and antipyretic: 

3— Saloli, 

Quininae sulphatis (vel hydrochloratis) . . . .. aa gr.lx 

M. et fiant capsulae no. xx. 
Sig. — Take one four to six times daily, before meals when near them. 

1$ — Quininan sulphatis gr. xxx 

Acetanilidi gr. xxiv 

Caffeinias citratis gr. iij 

M. et fiant pil. no. xij. 

Sig. — One every hour. (Endelmann.) 

The facial swelling resolves with the cure of the abscess or its proper 
venting, but may be assisted by cold applications or cataplasma kaolini 
to the outside of the face and by gentle massage by the patient or 
nurse. Indurated swelling may be assisted in reduction by the operator 
through vibratory massage. 

A piece of metal drilled through one end and mounted on a No. 303 
mandrel may be revolved while the engine handpiece is strapped to or 
held in the hand. 1 This imparts a vibratory motion to the hand useful 
when the lubricated finger-tips are pressed over the face or gums. 

The heat of a large electric lamp concentrated upon the face from a 
short distance, and followed by massage, is also useful in facial swellings 
due to cellulitis. 

1 W. H. Mitchell, Dental Brief, 1908, Academy of Stomatology. 



446 TREATMENT AND FILLING OF ROOT CANALS 

After the reduction of acute inflammatory symptoms the treatment is 
the same as in the forms of moist gangrene (which see). The canals are 
sterilized by formocresol for a time, then opened, dressed with anti- 
septics, and when the abscess is cured the canal is to be filled. 

Treatment of Chronic Apical Abscess. — As stated in the pathology, 
chronic apical abscess appears in three forms: 

1. With point of discharge through the root canal. 

2. With point of discharge through a sinus or fistula in the bone and 
gum or other soft tissue. 

3. Without point of discharge as a latent focus of pus formation 
within the bone or apical tissue (an encystment of the pus) (Fig. 515). 

1. In the first form the abscess sac consists of the apical tissue which 
has undergone more or less organization into fibrous tissue surrounding 
the cavity of the abscess, the lining of which continually undergoes 
solution into pus, which escapes via the open canal (Fig. 522). 

This is usually the sequence of the abortive treatment of acute 
apical abscess or of an open canal produced by caries. 

In the first variety the abscess cavity is usually of a size dependent 
upon the size of the acute abscess cavity and gradually grows smaller as 
the tissue organizes. In the second the abscess 
F,G - 522 cavity may grow gradually larger as food packs 

into the cavity of decay and produces stoppage 
or semistoppage of the canal vent (Figs. 505, 
506, and 508). According to the condition found 
by instrumentation or a>rays, or inferred by sub- 
sequent symptoms, the grades to be treated may 
be classed as : 

(a) Those in which acute abscess aborted has 
resulted in pus cavity closure to a point of al- 

Chronic apical abscess, .... 

third grade: B, abscess sac most obliteration. 

containing a central pus cav- /£) Those m w hich a small sac containing a 

itv; D, apex of root; C, canal . . 

containing pus. fair lumen is found. 

(c) Those in which a large fibrous sac exists 
and which is sometimes from one-fourth to three-fourths of an inch in 
length, with a corresponding lumen (Fig. 522). 

(d) Those in which the pus sac and bone is liquefied and the bone is 
more or less necrotic (Fig. 508). 

Gentle probing will usually give a guide to the extent of the abscess. 
The treatment for the first three grades consists of obtaining free access 
to and drainage of the abscess tract. This should be done with formalin, 
5 per cent, aqueous to full strength formocresol, in the canal to sterilize 
what infective material exists, and prevent extraneous infection. The 
sealing in of formocresol should now be done as in moist gangrene. 

If the infective material be not killed out there will be pus found 
in the canal. This should be removed after twenty-four or forty-eight 




DENTO-ALVEOLAR ABSCESS 447 

hours, and a new dressing applied. If after the first application no pus 
be found and no acute abscess be lighted up, the cotton dressing is 
more tightly introduced after appropriate canal enlargement if more 
be needed. 

Each dressing should be examined for pus and a dry cotton introduced 
to" take up any if a flow of it follow the removal of the dressing. Hydro- 
gen dioxid should not be forced into such an abscess, as great pain may 
result from the reaction with the pus and blood. 

When a tight cotton dressing has been in place a week and the canal 
dressing exhibits no odor of putrescence nor flow of pus, the root canal 
may be filled at least at the apex. In the third grade (c) an acute 
abscess is liable to be set up, although under formalin influence it may 
heal. 

In a relatively few cases teeth cannot be closed at all without a 
recurrence of trouble within a short period, which trouble is usually 
relieved by opening the tooth. The repetition of this is annoying, and 
in some cases is due to the strength of medicaments, such as formalde- 
hyd, which should be modified or abandoned for sedative antiseptics, 
such as phenol-camphor or euge"nol plus menthol. In some of the cases 
the gases may accumulate more rapidly than disinfection occurs. In 
other cases the irritability of the tissues seems to produce intolerance 
of any remedial measures. What is known as " systematic stopping and 
unstopping" seems sometimes to overcome the irritability and accustom 
the tissues to being covered. The system consists of stopping with eugenol 
and menthol or modified formocresol for about eight hours, or from 
morning to afternoon, then venting and redressing until the following 
morning, then for twenty-four hours, then forty-eight, then seventy- 
two, etc., until the tooth stays stopped. 

There have been a few patients who cannot seem to have teeth 
"treated," nearly all cases being practical failures even when aseptic. 
Some few may be kept in comfort for a while with permanent vents, 
but this is objectionable. The making of an artificial fistula should be 
attempted. In some cases the writer has found an error of diagnosis 
on his part in that apparent apical irritability has been due to a fine 
filament of ulcerated pulp in the extreme apical end of the canal. This 
having been punctured full of carbolic acid and removed, the case has 
proceeded to a cure. 

The fourth grade (d) is almost certain to cause reaction. In either 
case an external opening should then be made, establishing a fistula. 
If these grades can be diagnosticated beforehand, it is well to do this 
before canal treatment. 

2. Cases which have an established fistula are usually easy of treat- 
ment mechanically. 

In all cases the organized tissue lining the abscess tract is breaking 
down into pus and continually regenerating itself except in a fair number 



448 TREATMENT AND FILLING OF ROOT CANALS 

of cases in which the abscess cavity enlarges at the expense of the organ- 
izing tissue. This latter result is usually due to gravity, which confines 
the pus germs in crypts of the abscess walls. 

The canals should be made continuous with the abscess cavity. This 
is not always easy in molars, and, as a rule, canals which have sensitive 
tissues at their ends should not have this tissue lacerated. 

Instead, in molars, after due and moderate cleansing of canals an 
application of formocresol for twenty-four hours before thorough 
canal manipulation is wise. They are then freely opened and formo- 
cresol dressings placed in them. If the fistula does not show signs of 
healing in a week it should be washed out with antiseptics and the 
canal which did not have sensitivity at its end should be filled with 
a thread of cotton saturated with carbolic acid or phenolsulphonic acid, 1 
and pressure made upon it with raw vulcanite to force it through the 
foramen and into the abscess tract. A bit of cottonoid should be 
placed over the fistula to prevent the escharing of the mucosa. The pus- 
forming area is thus eschared, killing the invading bacteria and stimu- 
lating the tissue to regeneration. 

The canal is again dressed with formocresol and a week or more 
allowed. 

Hydrogen dioxid should be avoided in this connection, as it has 
forced the infective material into distant parts of the abscess tract 
without disinfecting it. 

The medicament may be drawn rather than forced through by the 
use of an unperforated rubber cup pressed upon the wet gum and then 
released. It acts as a vacuum cup (Fig. 522, a). This rubber cup may 
be mounted upon a tube having a shoulder filed on it and the tube be 
attached to the saliva ejector or a rubber bulb. 

If pus formation persist, and especially if the pus be found on the 
end of the dressing, or the foramen be widely open, the pus either 
flows into the canal and becomes a continuous cause of infection; 
or the cotton goes through the root end and acts as an irritant. In 
either case the filling of the canal is indicated. This forces all 
pus to remain external to the canal. The fistula should now be irri- 
gated with sulphuric acid, 25 per cent., to dissolve any calculi present, 
kill bacteria in the abscess crypts or cemental lacunae, and stimulate 
the tissue (Fig. 508) . Care is to be used not to eschar the oral tissues 
or affect the clothing of the patient. A minim syringe limits the amount 
used and a pad of cottonoid catches any excess if this be not used (Fig. 
520). If this fail after weekly attention for a month or more, there is 
probably dead bone or a dead and infected root end, and root amputa- 

1 Acid phenolsulphonic consists of 97 parts, by weight, of concentrated sulfuric 
acid and 93 parts, by weight, of phenol, kept at 100° C. for about twenty-four hours 
to produce a reaction, when sufficient distilled water is added to make the liquid assay 
about 80 per cent, of phenolsulphonic acid. (Buckley Lilly.) 




DENTO-ALVEOLAR ABSCESS 449 

tion is in order. There is an exception to this rule in some cases. The 
writer has had these fistula? heal up when let alone for a time, and if 
no signs of active pus formation are present this may be resorted to. 

In other cases the gravity of the pus alone has prevented healing, 
and when the patient has been instructed in the use of a Sub. Q syringe 
and antiseptic solution several times a day, the abscess has healed. The 
theory is that the constant removal of the pus has given the granulations 
opportunity to spring up. 

The use of the rubber cup (Fig. 519) as a vacuum cup draws pus 
from apical abscesses and stimulates a flow of fresh blood in the area. 
This blood is said to have a higher op- 
sonic index than normal blood, and hence FlG - 523 
greater phagocytic effect. It acts to 
massage the gum and may be applied by 
the patient. A small glass cup or rubber 
cup with rubber bulb attached may be 
used for the purpose. (See previous de- 
scription.) 

The amputation of root apices, while 
not always productive of the desired heal- 
ing, at least benefits the Case. Amputation of root apex: OG. 

A radiograph is a Useful guide tO the opening in the gum made by packing 
. . Pi' i • ii c fistula; AC, abscess cavity; RF, root 

position oi root apices, and especially or fi i Iing . 

the root causing the abscess if not known 

(Fig. 515). When located, the fistula should be lanced open and the 

orifice in the bone enlarged, if necessary. 

The abscess cavity is then packed with gauze until the root apex is 
visible; it is then removed by means of a dentate fissure bur laid against 
its side. The canal must previously have been solidly filled with gutta- 
percha or oxychlorid of zinc. The root should be trimmed down with 
burs to a point below the healthy bone level. All necrotic bone is to be 
removed (Fig. 523). 

A variant of this operation was introduced by M. Schamberg. It 
consists, after root location by instrumentation or radiograph, of 
entering the diseased area with a surgical bur and cutting away the 
root. This is the simpler technique, if one be sure of his position. 

For a short time this cavity may be packed with gauze, or a clot may 
be invited, the mouth and parts kept sterile, and the case watched. If 
necessary, stimulation of the tissue by silver nitrate or scarification 
should be employed. 

The part heals by granulation and new bone is generated. 

When the fistula is upon a perforation near the root apex, or a much 

lacerated foramen, the canal may be filled with oxychlorid of zinc, 

which is allowed to go through the opening into the fistula. The excesg 

of this is removed after partial hardening of the material. In fistula? 

29 



450 



TREATMENT AND FILLING OF ROOT CANALS 



located upon low lateral perforations, either oxychlorid of zinc or 
oxyphosphate of copper are worked through and allowed to set. The 
excess in the fistula is then removed. 

If in any case this does not heal, the fistula is to be packed open 
with gauze and a retention cavity made in the root side if accessible. 
This is filled with a tight amalgam, compressed air being used to 
keep the part dry. If impossible to keep dry, the cavity is touched 
with silver nitrate and the filling well compressed under a stream of 
water. 

Time for healing may be required in some of these cases. If these 
latter cases will not heal, or the filling methods are not successful or 
possible, extraction and replantation is the last resort, if the tooth be 
valuable. 



Fig. 524 



Fig. 525 



Fig. 526 




A skiagraph of apical ab- 
scess cavity about two root 
apices; incurable by ordi- 
nary means. 





The Fame after root 
amputation. 



The same thirty daya 
later, showing a certain 
amount of new bone for- 
mation. (Price.) 



An impression is taken with the tooth in place, and a splint is con- 
structed over the model, the occlusion being considered. The tooth is 
extracted, the abscess tract curetted, and the alveolus packed with 
antiseptic gauze or cotton tampon saturated with 50 per cent, phenol- 
sodique. 

The tooth apex is slightly cut off, the canal opened from the apex, 
and the tooth dropped into a germicidal solution, as lysol, 5 per cent., 
or 50 per cent, phenol-sodique. 

After a time it is dried, the canal filled with gutta-percha, the per- 
foration filled, and the tooth returned to the solution. 

The tampon is removed, the socket again syringed out, when the 
tooth is returned to place, the part dried, and the retaining device 
cemented in place. This should remain in place for about eight weeks, 
to allow reunion or ankylosis to occur. 

If the parts be badly infected, it may be well to allow a few days to 
elapse between the extraction and the replantation. In the interim 
the tooth may be prepared. If the tooth is to be replanted in a new 



DENTO-ALYEOLAR ABSCESS 451 

position the tooth must be cut from the plaster model, a hole drilled 
in the base of the model and the tooth put in its proper relation. The 
splint is then constructed. At the time of replantation the socket may 
be freed of clot and any granulation by the use of a bone reamer gently 
applied. In some cases the transplantation of another tooth or root 
with an artificial crown upon it may be done instead of replanting the 
tooth. (See chapter on Plantation.) 

Fistulae upon the Face. — If a fistula be formed upon the face it will 
usually heal if the root canal can be made continuous with the abscess 
tract and no necrotic bone be present other than that usually formed 
by a chronic abscess. This done, the treatment is the same by means 
of formocresol sealed in. If pus ceases to form, the apex of the reamed 
canal may be filled with gutta-percha made antiseptic with aristol or 
iodoform, formocresol placed in the remaining open canal, the tap 
sealed, and time allowed for healing. If it will not heal, amputation 
and bone curettement may be done from within the mouth. Still failing, 
extraction is the final resort. These fistulae heal with least scar if the 
tooth be not extracted (Fig. 509). 

If cicatricial tissue form within the cheek tissue it may bind the 
cheek tissues to the bone in such a way as to cause a depression of the 
facial scar. To remedy this a cut should be made in the tough fibrous 
cicatricial cord from within the mouth, while the cheek is drawn outward. 
A pin is to be passed through the depressed portion of the facial cicatrix 
and a small compress of gauze laid under each end (Black). This 
raises the centre of the cicatrix, separates the cut ends of the cord, 
and permits a new growth of tissue to reunite it into a cord of greater 
length, which causes less binding (Fig. 510). 

Fistula in the Antrum of Highmore. — In recent cases this may consist 
of a simple fistula discharging pus into the antrum. The diagnosis can 
only be made inferentially when an acute abscess in the region has 
suddenly subsided, and actually by pressing a fine probe or forcing a 
stream of antiseptic fluid through the root canal into the antrum, or 
by skiagraphy. If treated like any other fistula by way of the canal, 
it should heal, and some cases seem to have done so. In long-con- 
tinued cases, with general septic inflammation of the antral mucosa 
and offensive discharge into the nasal cavity, the antrum must be 
opened. The mucous membrane of the patient is anesthetized and 
an opening made through the lower buccal wall of the antrum large 
enough to permit of satisfactory examination. After sterilization of 
the antral cavity, all necrotic bone should be removed, and the 
antral cavity irrigated with antiseptics and packed for a period with 
a long strip of antiseptic gauze fed directly from a wide mouthed 
bottle in which it has been kept. Later it may be irrigated for stimu- 
lation, with Lugol's solution (liquor iodi compositus, gtt. xx to the 
ounce), or upon occasion even with pure tincture of iodin or an alcoholic 



452 TREATMENT AND FILLING OF ROOT CANALS 

dilution of it. The root canals should preferably have been previously 
sterilized and filled. If necessary the root apex affected may be ampu- 
tated at the time of operation. After healing of the antrum, if the 
opening does not heal, a slight plastic operation upon the mucous 
membrane will usually close it (Fig. 504). 

In all irrigations of the antrum the head should be inclined forward 
over a basin to allow the solution to run out of the nasal cavity. In 
using iodin it is well to pack the nostril on the affected side with cotton, 
removing it after the irrigation. 

In cases in which the pus finds its way along the root of the tooth 
and discharges at the gum margin, there is liable to be more or less 
calculus deposited upon the root surface, causing it to simulate a case 
of pyorrhea alveolaris. The calculus may exist also at the apex in some 
old cases of chronic apical abscess with the ordinary form of fistula. 
This calculus should be removed with pyorrhea instruments or by 
injection of 10 to 25 per cent, sulfuric acid. Otherwise the cases do 
not differ from the ordinary. 

Systemic Complications. — The cachectic, debilitated, anemic, tubercu- 
lous, and syphilitic are liable to extensive pus formation, which enlarges 
the cavity unduly and may involve the roots of other teeth or even 
cause devitalization of their pulps, which aids in the continuance of the 
abscess by adding a fresh cause. 

In such cases all the dead pulps should be removed after careful 
diagnosis, and the patient should be instructed in the use of a Sub. Q 
syringe and a mild antiseptic, the object being to keep the dependent 
parts free of pus and allow granulations to form rather than be con- 
stantly broken down. 

In addition, such systemic medication or remedial measures as will 
raise the recuperative and resistant powers of the tissues should be 
employed. 

If very persistent, a vaccine may be employed, after the method 
of Wright, to raise the opsonic index. (See chapter on Pyorrhea 
Alveolaris.) 

The direct results of infection toxemic and septicemic, have already 
been considered (see p. 445). 

3. In the third class of cases the diagnosis is either made because 
of a latent swelling on a filled tooth or cyst of fluid contents overlying 
a root apex, or because of subacute apical irritation, which either 
opening the tooth demonstrates to be due to septic causes, or a radio- 
graph shows to be an abscess cavity. The presence of eruptions upon 
the body not otherwise accounted for or other evidence of toxemia 
should cause these latent abscesses to be sought as the source of toxic 
effects. In the case of a cyst a fistula should be established ; in the 
other the canals should be opened and the tooth treated as for the 
first or second grade of abscess discharging via the canal. 



DENTO-ALVEOLAR ABSCESS 453 

Necrosis and Caries of Bone. — In some cases the inflammatory reaction 
is so severe that some of the bone may be involved en masse. 

This is fortunately unusual, the usual result being a liquefaction 
of both soft and hard tissues. If it occur as a sequestrum, this gradually 
loosens, and either appears at the fistula as one or more pieces, or, being 
found loose, by instrumentation is worked out, the fistula being en- 
larged if necessary. If the thorough loosening of the pieces is awaited, 
the patient should syringe out the abscess tract with antiseptics, and 
the operator should see the case frequently until the operative pro- 
cedure is necessary. The general health is to be improved if necessary. 

Ulceration of an alveolus may result from the extraction of a tooth, 
and if neglected may produce necrosis of the bone. In both cases the 
pain is severe and often reflex. The condition has been termed "dry 
socket." 

If ulcerated, the alveolus is painful to touch; if necrotic, the super- 
ficial bone is insensitive, the ulceration being more deeply seated in the 
diploeic structure. 

The best and most radical treatment consists in antisepsis followed 
by the administration of short general anesthesia, or, if necessary, 
cocainization of the gum and a thorough removal of the superficial 
ulcerated or necrotic bone to a point capable of healthy granulation. 
After injection, a clot is invited to fill the alveolus in order to stimulate 
the condition following an ordinary extraction. 

As an alternative, the ulcerated cases may be thoroughly saturated 
with full strength trichloracetic acid solution, which acts as a stimulant, 
escharotic, and germicide, and a paste made from orthoform, zinc 
oxid, and vaseline may be packed into the alveolus. 1 The patient 
should be seen not later than twenty-four hours afterward, and the 
application repeated, or, better, a clot invited after further sterilization. 

Hydrogen dioxid with mercuric chlorid added (1 to 1000) and applied 
topically is effective as a germicide. In caries of the bone a progressive 
absorption of the cancellated bone and subsequent suppuration of its 
marrow results in a honeycombed mass of dead bone which tends to 
become gradually large. It should be removed and regeneration invited. 

Abscesses on the Temporary Teeth. — The treatment of abscess in 
case of temporary teeth being effected, does not differ in principle from 
that in the permanent teeth. The only complication is the state of the 
root end, whether partially absorbed or not. A plastic root filling is 
indicated, the conditions being met by paraffin or wax combined with 
aristol or paraform. (See Root Canal Filling.) If the roots are almost all 
resorbed, extraction is often better than canal treatment (Fig. 527). 

Suppuration following Extraction. — When the suppurative process is 
active, whether in the second or third stage or when a fistula exists, 

1 Jack, International Dental Journal, 1905. 




454 TREATMENT AND FILLING OF ROOT CANALS 

the surrounding tissue is sometimes involved to such an extent that 
whether the tooth be extracted or not the process may continue. It 
lias happened that adjoining teeth have been involved or that the 
infection may travel along the periosteum and cause profound and 
widespread infection. In a case of a boy aged 14 years, at present 
under treatment, a right lower molar was the starting point from 
which the infection spread along the bone, so that every lower tooth 
from the right second molar to the left second molar was profoundly 
loosened, the gum detached, and the chin tissues swollen. Pressure 
upon them caused a copious flow of ichorous pus from a number of 
fistulse and gum margins. The patient suffered from aneurysm due to 

the aseptic intoxication. The case referred 
Fig. 527 to the writer was sent to a surgeon, who 

made a lineal incision beneath the rim 
of the jaw, and after irrigation packed 
with antiseptic gauze. The case is pro- 
gressing satisfactorily, with some hope of 
saving a fair number of the teeth, which 
are becoming more firm. 

Such cases illustrate the dangers of apical 
infection and the necessity for supervision 
after treatment or extraction in all cases 
showing the relations of an abscess f abscess. The removal of the primary 

upon a temporary tooth, with the . . . .... „ 

crown of a developing permanent eXCltlllg CaUSe and active Sterilization 01 

tooth underlying it, tne p arts j s indicated. Systemic treatment 

should be conjoined. 

Non-septic Pericementitis. — This form of inflammation of the peri- 
cementum is non-infective, and is due to some form of violence or 
chemical irritation of the pericementum or is the result of a violent 
pulp reaction by reason of which some of the excess of blood in the pulp 
finds its way into the apical tissue. 

In all cases there is an overfulness of blood in the apical tissue asso- 
ciated with swelling, which causes the tooth to be somewhat extruded, 
therefore it maloccludes, which adds more mechanical irritation. 

In so far as canal treatment is concerned the cases may be divided 
into: 

1. Those in which the violence has been or is of external character, 
the cause not continuing in action or being present only as malocclusion ; 
sometimes as a wedge or regulating appliance. If the pulp be not 
hopelessly involved the treatment should consist of rest attained by 
means of guards to prevent occlusion and counterirritant applications 
upon the gum over the tooth in mild cases, distant in severe ones, or 
the use of depletion and sedation in severe cases. As an oral sedative, 
cold aqueous extract of hamamelis is very useful. Derivation should 
also be employed. 



DENTO-ALYEOLAR ABSCESS 455 

Traumatic pericementitis may cause a profound swelling of the peri- 
cementum and extrusion of the tooth which only replantation will cure. 

2. Those in which by way of the canal the apical tissue has been 
lacerated by broaches or drills, irritated by pressure of air, canal fillings, 
etc., or chemically irritated by powerful chemical substances. Second- 
ary hemorrhage after pressure anesthesia and pulp removal is a mechan- 
ical cause. In all cases such should be avoided, or, if present, removed, 
and sedatives, such as phenol-camphor or eugenol, to which menthol has 
been liberally added, should be placed in the canal on cotton. Counter- 
irritants are to be applied to the gum and, if necessary, guards applied 
to prevent occlusion. 

When canal fillings have been carefully made they sometimes cause 
a limited non-septic apical pericementitis, which will often pass away 
under the action of counterirritants ; therefore some judgment must 
be exercised as to the removal of such canal fillings. 

Perforations and Resorptions. — The same accidents that occur in canal 
opening in the case of the removal of anesthetized or devitalized pulps 
may occur in all gangrenous cases with somewhat increased liability 
to infection of the pericemental tissue. 

In old cases the pericemental tissue may hypertrophy, causing the 
condition of hyperplastic (fungoid) gum. This should be sterilized and 
then may be frozen with ethyl chlorid and ablated with sharp instru- 
ments, or it may be saturated with trichloracetic acid and ablated, or 
it may be pressed away (resorbed) with cotton saturated with tincture 
of iodin or an antiseptic oil. The perforation is then covered. 

The Filling of Perforations. — Perforations made high up in the canal, 
after being appropriately sterilized with formocresol, should be filled 
with wax or with gutta-percha cones, which 
have been accurately fitted to the openings. FlG - 528 

It is often difficult to do this, but the effort 
should be made. When ready, a little anti- 
septic chloropercha is to be placed in the 
perforation or upon the cone, and the latter 
packed to place. 

In low perforations without a fistula asso- 
ciated, the opening of the perforation should 

. . - . ... lin i e Idiopathic resorption of perma- 

be enlarged inwardly and a ball or plaque ot nent root . The bay upon the side 
aseptic, warm, low heat gutta-percha, or even exposed the P ui P and perforated 

. . , . the root as shown. Crater-like 

temporary Stopping, adapted tO the Opening. resorption about apical foramen 

A piece of pure gold plate mav be burnished Pu 'p first ^vitalized on account of 

., i . _ . . . persistent pain and the tooth later 

over an accessible opening, and be adapted extracted. 
with thick chloropercha or temporary stop- 
ping. Any of these may be fixed in place with oxyphosphate of zinc. 
Quick-setting oxyphosphate of copper in its soft, gummy state may be 
painted over the tissue and root opening by means of an instrument, 



456 TREATMENT AND FILLING OF ROOT CANALS 

or , the perforation may often be satisfactorily closed with copper 
amalgam. When in posterior teeth a pin must be used, the pin may be 
made smaller than the root canal and be coated with wax, soft oxy- 
phosphate of copper is put in the canal, and the pin gently thrust in. 
When the cement has set the pin may be heated and withdrawn, and 
when included in the intended superstructure, the pin may be again 
cemented in place. 

When a perforation threatens to produce an abscess an artificial 
fistula should be made and the case treated as described on page 447. 

If a perforation have a fistula associated with it, the oxyphosphate 
of copper may be allowed to go through the fistula, by way of which any 
excess may be removed. 

In case of resorption of the roots of permanent teeth great difficulty 
may present, the soft, absorbent tissue having grown into the cavity in 
the root side which it has made. A radiograph will aid in determining 
the extent of the lesion, which usually renders canal treatment impossible 
and extraction imperative. 

THE FILLING OF ROOT CANALS 

In all cases in which the removal of the dental pulp from the canals 
is necessary, it is imperative that the pulp canals shall be filled with 
some substance that shall mechanically obliterate it by sealing it 
throughout its length in order to prevent the ingress of fluid either 
from the mouth or apical tissue. Such fluid is liable to putrefaction, 
and the results of putrefaction follow. If made antiseptic, it also 
tends to kill any bacteria which may find a partial entrance. The 
mechanical sealing may be defective, even when the best possible 
effort has been put forth to make it perfect, so that the addition of 
more or less permanent antiseptics is valuable. 

It matters little whether a canal filling is hard or soft provided it is 
permanent, that the above conditions are fulfilled, and that it is not 
disturbed by any subsequent work. 

It also makes very little difference whether the pulp has been removed 
while aseptic or has been in a septic state, provided the canal has been 
rendered sterile by appropriate means. 

In other words, when the canal is aseptic and the apical tissues 
sterile and healthy, the canal is ready for filling. The length of time 
this may require also makes no difference The size of the apical foramen, 
the presence of inaccessible apical portions of canals, the presence of 
perforations and some other conditions, however, indicate a choice of 
some root filling rather than others, so that there is no absolute rule for 
all cases. The following root canal fillings are useful. 

Gutta-percha. — This is usually the ordinary, low heat, pink gutta- 
percha base-plate containing vermilion and zinc oxid. Cones may be 



THE FILLING OF ROOT CANALS 457 

rolled or left with flat sides. Prepared cones may be purchased which 
have an accurate taper and are either round- or flat-sided. The flat side 
permits any adjunct plastic filling material or solvent to flow down the 
side of the cone rather than be forced toward the apex. 

Temporary stopping may be melted in a spoon and aristol added 
to it. It is then rolled into cones for use. Instead, a stick of it may 
be warmed at a point away from the end and then be pulled out into 
two cones, which may be further rolled out. They may be rolled in 
powdered aristol if desired. 

Chloropercha. — This is a solution of gutta-percha base-plate in chloro- 
form. Usually a quantity of aristol or iodoform is added to make it 
antiseptic. As it shrinks in hardening it should be used in conjunction 
with gutta-percha cones or carried upon cotton twist or floss silk, which 
it saturates, transforming them practically into a solid mass when the 
chloroform evaporates. 

Eucolypto-percha (Eucapercha) .— The basis of this substance is a 
solution of gutta-percha base-plate in eucalyptol. To this various 
antiseptics may be added. There are various modes of making this 
substance. B. L. Cochran 1 suggests the following: 

1$ — Gutta-percha base-plate 5 S 9 

Dissolve in chloroform q. s. to a thin solution. Add satu- 
rated solution of thymol in eucalyptol f§ss 

Let the chloroform evaporate. 

Eucapercha Compound (Buckley Lilly) is a simple solution of base- 
plate in eucalyptol made by aid of heat. 

Formopercha (Blair) has paraform and oil of cassia added. 

This material may be warmed into a creamy paste and be used either 
on cotton or be used in conjunction with gutta-percha cones. 

Zinc Oxychlorid. — This consists of the ordinary zinc oxychlorid cement, 
which consists of modified calcined zinc oxid for the powder and diluted 
zinc chlorid as the fluid. 

It is antiseptic for a time at least, and may have iodoform incorporated 
with it if desired. It is carried to place on a thread of cotton, or may 
be used with gutta-percha cones. The addition of a trifle of glycerin 
retards setting. 

A so-called embalming paste is prepared as follows : 

1$ — Paraform 1 part 

Thymol 1 part 

Glycerin 1 part 

Zinc oxid 1 part or more 

Or, 

1^ — Paraform 1 part 

Thymol 2 parts 

Alum 1 part 

Zinc oxid 2 parte 

Creosote to a thick or thin paste. 

1 Dental Review, 1905. 



loS, 



TREATMENT AND FILLING OF ROOT CANALS 



This is used as a temporary germicidal canal dressing on cotton or 
as a root filling with gutta-percha or temporary stopping cones which 
are pressed into it. 



Fig. 520 



Fig. 530 





root portion of pulp; 6, mummifying paste; 
phosphate; d, gold or amalgam. 



zinc 



Root-canal filling: A, gutta-percha 
B, zinc oxychlorid. 



Wax or Paraffin. — Either of these may have a third of its bulk of 
salol, aristol, or iodoform, or a fifth of paraform added to it while melted 
in a spoon. It is then rolled into cones or small pellets. In use a pellet 
is dropped into the dried pulp chamber and a hot Evans root drier 
point applied. As it melts, the metal point is carried down into the 
root and the fluid material pumped to the apex. Capillarity does 
part of the work. It adjusts itself to the tissue and the canal walls. 
The pulp chamber is then cleared of excess wax, etc., and filled without 
pressure. 



Fig. 531 



Fig. 532 





A, perforation through side of apex; D, cone 
of gutta-percha passing through; B, portion to 
be cut off; C, portion of canal not treated. 



Lateral perforation due to holding a bur at a 
wrong angle to the axis of the root: A, root 
canal subsequently filled with gutta-percha; B, 
perforation filled with a fitted cone of gutta- 
percha; C, zinc oxychlorid. 



Salol.— This is a solid antiseptic, melting at 104° F. It is used much 
as paraffin is. A gutta-percha cone may be thrust into it while fluid. 
It often seems to disappear from canals, and unless used with paraffin 
is to be used only as a temporary root filling. 

Canada Balsam. — A solution of Canada balsam in chloroform to which 
hydronaphthol is added (Williams) makes a useful solution in which 



THE FILLING OF ROOT CANALS 459 

to saturate cotton twists or to moisten canals previous to the introduc- 
tion of a cone of gutta-percha. 

Normal Tapering Well-opened Canals. — In these canals gutta-percha 
is admirable; a little eucalyptol is applied to the canal walls and a 
section of a suitable cone mounted by heat on the end of a canal plugger 
which will go to or nearly to the canal end is gently but firmly pressed 
into the apex of the canal. Temporary stopping cones are more 
readily adapted, and as they can be made antiseptic, are valuable. 

The rest of the canal is then filled with other sections or with zinc 
oxychlorid made thin and carried to place on cotton twists. The latter 
may be used for the entire canal, and should then be preceded by a 
tiny bit of cotton saturated with an essential oil to prevent irritation 
of the apical tissue. It is claimed that this cotton is acted upon by 
the zinc chlorid being transformed into an amyloid condition. 

A variant consists in moistening the canal with chloropercha or 
eucalypto-percha, and using the section of cone or pressing in an entire 
cone. A second cone may be placed at the side of the first and both 
compacted after warming with a hot air blast, or the first cone alone 
used. 

Ottolengui advises the use of bits of floss silk an inch long to be 
saturated with chloropercha and dried. These are to be pressed into 
chloropercha previously placed in the canal and crimped to place. An 
end is left projecting into the pulp chamber. If necessary this may be 
caught and the dressing withdrawn. 

Another variant is the use of chloropercha on cotton, which makes 
a very accurate and easily introduced root filling when carried to 
place on a properly formed and tempered Swiss broach or prepared 
Donaldson bristle. 

When the broach must be bent to enter canals, loosen the broach first 
before introducing into the canal, thus leaving the cotton loosely mounted 
on the broach. To prepare a Donaldson bristle cut off the hook and 
flatten the end upon an Arkansas stone, then lay upon a glass slab 
and burnish thoroughly to remove any bur left. In use the cotton 
and broach are rolled with the left forefinger and thumb only. It is 
obvious that to do this the broach must be perfectly straight. The 
writer believes the prepared Swiss broach not only more facile but 
economical in use. 

To prepare broaches, select accurately tapering Swiss or English 
broaches from which the temper has not been drawn. Next, draw the 
temper to a blue color by placing a few in a test-tube and heating first 
at the shank, gradually drawing the tube over the flame toward the 
points; let cool on any open surface. The point is left if canal explora- 
tion is intended. For carrying cotton twists, cut the end off with scissors. 
To wind the cotton lay a wisp on the left forefinger, lay the broach upon 
it, close down the thumb, then quickly revolve the broach with the 



460 TREATMENT AND FILLING OF ROOT CANALS 

right forefinger and thumb, stroking the cotton with those of the left 
hand into a symmetrical cone. To use as a swab, rotate in the canal 
to the right. To leave the cotton in the canal, rotate to the right as 
the twist is pressed to the apex. Then turn the broach once or twice to 
the left to loosen it from the cotton, withdraw a little, then press in again. 
Thus the cotton is crimped upon itself. 

Roots with Open Foramina. — These may be incomplete roots with 
very large apical openings, in which case wax with aristol is the best 
filling used, as previously stated. It should be said again, however, 
that if possible the pulps of such a tooth should be capped to permit 
root formation to be completed. 

If the foramen is of moderate extent and either natural or unfortu- 
nately made with drills, gutta-percha cones are valuable. To determine 
the size of the cone, one of two methods may be employed. Perhaps 
the more accurate is the employment of a series of gradually increasing 
sizes of canal pluggers. One should be selected which will just fit the 
apex or be a trifle too large. By placing this in the hole of a draw 
plate, a specially rolled cone or even a slightly tapering size may be 
made to fit the hole in the plate. The canal is moistened with euca- 
lyptol or chloropercha and a quarter-inch section of the cone is carried 
on the plugger to its place in the root canal apex. A slight protrusion 
is not ordinarily productive of injury. A cardboard perforated by 
the respective plugger will do instead of the draw-plate. If the root 
length was previously measured with a piece of rubber dam slipped 
over the plugger shank and some known point on the tooth used as a 
guide, the cone should be seen to go down until it chokes the foramen, 
when the dam should be above the guide point a distance equal to the 
length of the cone section used. 

In the second method a long, tapering cone is prepared. Some 
point on this must fit the foramen. It is tried in and as often as sensa- 
tion is felt it is cut off a trifle and tried again until it chokes the foramen 
without sensation. 

In case of abscess, especially if filling is a means to a cure, this may 
extend beyond the apex of the tooth. 

The cone should be marked at a point corresponding to the guide 
point chosen and laid aside. Next, a fine hook made by bending 
the tip of a fine broach to a right angle, then cutting it close to the 
shank, has a piece of rubber dam slipped over it and is passed through 
the apex and hooked upon the edge (Fig. 533). The dam is slipped to 
the chosen guide point. The probe hook is withdrawn, the dam laid 
at the mark on the cone, and the cone cut off at the lower edge of the 
hook (Fig. 533, b) . In use, a little solvent, preferably chloropercha, is 
placed in the canal and the cone slowly slipped to place until the mark 
coincides with the guide point. The cone is then cut off with a hot instru- 
ment, warmed, and gently packed into the canal. 



THE FILLING OF ROOT CANALS 



461 



When the canal has been reamed with a small engine reamer, and 
the apex enlarged, the hook may be placed and have a bit of rubber 
dam on it as a guide. Then slip a bit of dam over a larger tapering 
root reamer at a corresponding length. Drive the reamer in until at 
the guide point. This gives a tapering cone shape to the canal and is a 
guide in the construction of the cone (Fig. 534) . 



Fig. 533 



Fig. 534 





-b 



Manner of measuring the length of a root 
and fitting a gutta-percha cone. 



Manner of tapering a canal to fit a cone 
of the same size. 



Canals with Inaccessible Apices. — Any tissue in such apices should 
have been mummified or sterilized with formocresol or be treated 
by Rhein's method 1 of filling a canal with mercuric chlorid in hydro- 
gen dioxid (1* to 500), passing in a zinc probe, then applying the 
anode of a cataphoric outfit with from 1 to 5 milliamperes of current 
from three to seven minutes (the cathode at the cheek). The object 
is to form zinc oxychlorid in the apical root canal through electro- 
lytic action. The canal must be regarded as doubtful, but if well 
opened to the inaccessible portion a trifle of formopercha may be placed 
on cotton at this point and the balance of the canal be filled with anti- 
septic temporary stopping. The paraform and cassia in the formo- 
percha are active agents. 

A variant consists in the use of embalming paste or Soderberg's 
mummifying paste, either made stiff and introduced with successive 
sizes of pluggers, beginning with the largest admissible and proceeding 
to the smallest, or moistening the canal with the thinner paste and 
packing a cone into it. The use of such a paste in connection with a 
cone of gutta-percha is valuable as an agent embalming the fibrils in 
the dentin of teeth from which living pulps have been removed, or of 
keeping sterile the tubules of those teeth in which the pulp is gangrenous. 

If conditions admit of it, provision for future entrance of the canals 



1 Dental Cosmos, 1905, p. 1196. 



462 TREATMENT AND FILLING OF ROOT CANALS 

should be made, and it is always well to divide the operation of canal 
filling and crown filling by a short period of time. 

Iodoform paste with or without cotton may be placed in the upper 
third of the canal. 

Root Canals in Temporary Teeth. — These may at times be well filled 
with gutta-percha points, which, if aseptic, do not interfere with resorp- 
tion, but a material of easier adaptation which absorbs with the root 
is preferable. The waxes meet the indications, as they can be pumped 
while fluid from the action of a hot root drier into all inequalities, where 
they adjust their relation to the soft tissue. 

Buckley recommends in cases of chronic abscess the use of a stiff 
mixture of calcium phosphate and formocresol (formalin, 1 part;cresol, 
2 parts), to be packed into the pulp cavity and zinc phosphate flowed 
over it. 

Johnson recommends eucalypto-percha to be pumped into the canals 
and pressure with temporary stopping to be exerted until the solution 
appears at the fistula. Such temporary stopping as does not interfere 
with filling integrity should be left. 

There are various other methods of filling root canals, such as driving 
wood points saturated in carbolic acid into the canals; the use of iodo- 
form paste with or without cotton, or of creosote on cotton (preferably 
raw cotton) ; the use of balsam del deserto, etc., which have advocates, 
but the methods given are those which have had long-continued and 
successful use. 

The Covering of the Root Canal Filling. — The bulb of the pulp chamber 
may be filled with any of the more solid materials. In case of a strong 
crown, temporary stopping makes a good occupant of this cavity, 
although gutta-percha is often used. In the weaker teeth or sometimes 
for other reasons zinc oxychlorid or zinc phosphate with about 5 per 
cent, of thymol added while mixing makes a good filling. 

Mummification of the Pulp. — In order that time may be saved, efforts 
have been made to introduce partial removal of the pulp and the treat- 
ment of the remaining portion by means of drying agents which shall 
render it less liable to putrefaction. The method had its origin with 
Witzel in 1874, and has since been taken up by Miller (1893) and 
Soderberg (1895). 

It consists of partial devitalization by arsenic and the application of 
a tanning agent against the pulp stumps. Necessarily this causes the 
shrinkage of the organ, leaving a space about it into which bacteria may 
possibly find their way. Obviously the nearer the apex of the pulp canal 
this is carried, the less the danger of subsequent infection. Therefore 
the logical conclusion is that all remnants of pulp that can be removed 
should be removed, when a tanning and antiseptic agent that will 
occupy the canal becomes an excellent root filling. There is little 
excuse for not carrying the canal work to this point, as the present 



THE FILLING OF ROOT CANALS 463 

methods of canal enlargement render it facile. In some cases, how- 
ever, Soderberg's method may be of use. 

It consists in applying arsenic for a short time to devitalize the pulp 
bulb only, then applying a portion of the following paste to the pulp 
stumps : 

1$ — Aluminis exsiccatis, 
Thymolis, 

Glycerini aa 5J 

Zinci oxidi, q. s. to make a stiff paste. 

This is then covered with zinc phosphate and the filing completed. 
A crystal of cocain may be added to prevent pain. It has been suggested 
that paraform or a drop of liquor formaldehyd be added for the increased 
mummifying effect. 

Pulp Digestion.— Harlan recommended that the following paste be 
applied to unremoved portions of dead pulps as a means of digesting 
them preparatory to root filling: 

1$ — Papain gr. v 

Price's pure glycerin TRiv 

Sol. 1 : 200 hydrochloric acid 1T|y — M. 

This is applied in the pulp canal, covered with blotting paper, soaked 
in liquid vaselin, and the whole temporarily sealed for a few days. 
The pulp is reduced to the consistence of jelly and can be readily washed 
out. 

The method, on the whole, does not seem preferable to either mummi- 
fication or the Rhein treatment or the formocresol treatment of inex- 
tricable portions of pulps in curved roots, etc., inasmuch as the occupancy 
of a canal by a sterile pulp remnant is better than leaving an empty 
root canal apex or filling only a portion of it in such manner as to render 
subsequent treatment almost impossible. In fact, it is better that den- 
tists recognize their limitations and put themselves in position to do 
future good to the patient, than to blindly obstruct efforts in that 
direction. 



CHAPTER XV 
PYORRHEA ALVEOLARIS 1 
By EDWARD C. KIRK, D.D.S., Sc.D. 

Definition. — "Pyorrhea alveolaris" is a generic term which, strictly 
defined, means a flowing of pus from an alveolus. It describes merely 
a symptom which is usually, but not invariably, attendant upon a 
variety of gingival disorders. The term is applied in clinical dentistry 
to a complexus of pathological conditions which more or less clearly 
indicate a specific disease. As now understood, the term pyorrhea 
alveolaris includes those cases of morbid action characterized by the 
following features: Inflammatory degenerative changes leading to a 
molecular necrosis of the retentive structures of the teeth (their liga- 
ment, the pericementum), an atrophy of the alveolar walls, together 
with a chronic hyperemia of the gum tissue. After a variable period 
the teeth drop out, and the morbid action ceases with their loss. An 
examination of the roots of the teeth before or after their exfoliation 
usually, though not invariably, exhibits deposits of calculi upon their 
surfaces. The disease is generally, although not always, attended by 
a flow of pus from the alveoli. 

History. — That pyorrhea alveolaris is not a recent disease, or one 
due to modern constitutional states alone, is rendered evident from the 
examination of the skulls of ancient as well as modern races. The 
alveolar processes of many crania widely separated both in time and in 
locality exhibit marked impairment of structure which bears the closest 
resemblance to that presented by processes which are known to have 
been the result of pyorrhea during life. 

Recorded observations of this disorder date at least as far back as 
1728, when Pierre Fauchard described its essential clinical features, but 
failed to designate it by any specific term. Following this, communica- 
tions describing the disease were published by Jourdain in 1778, by 
Toirac in 1823, and by M. Marechal de Calvi in 1860, in which it was 
described as a "conjoint suppuration of the gums and alveoli," pyorrhee 
inter-alveolo-dentaire and gingivitis expulsiva respectively. 

1 The historical portion of this chapter and the definition of the disorder, with 
some modification of the latter, is the work of the late Prof. C. N. Peirce. 
(464) 



HISTORY 465 

The most important contribution to the knowledge of the nature of 
the disease which had up to that date been made was by Dr. E. Magitot 
in 1867. In his paper he describes the disease as being characterized 
by a slow but progressive inflammation destructive of the periosteal 
membrane and cementum, proceeding from the neck to the apex of the 
root and involving the loss of the teeth. From the exact seat of the 
lesion he designated the disease osteo-periostite aheolo-dentaire. Soon 
after the appearance of the periosteal inflammation, it becomes compli- 
cated with diseases of the gums and the osseous walls of the alveolus, 
although these are never primarily the seat of inflammation. Magitot 
regarded the causes of the inflammation as very complex, and to be 
sought for not in the teeth and gums, but in certain conditions of the 
general nutrition. The gouty and rheumatic presented the disease most 
frequently, although its presence in those suffering from diabetes and 
albuminuria was extremely common. The deposition of tartar on the 
roots of the teeth, which might at first glance be regarded as playing an 
important part in the causation of the disease, Magitot considered as 
accidental and not to be looked upon as a causative agent. With refer- 
ence to the efficacy of any treatment, however, he advised the removal 
of the tartar as an indispensable preliminary. The points of diagnosis 
differentiating between this condition and the former, that of gingivitis, 
however severe, were also clearly recognized and noted. 

Following Magitot 's able paper was one by Serran in 1880, in which 
the author took exception to certain of Magitot 's views, as well as to the 
term by which the latter proposed to designate the disease. He recog- 
nized, however, that the disease was most common in middle life and 
occurred principally among the gouty, the diabetic, and the albuminuric. 
He believed that the primary manifestation was a local congestion of 
the gums, followed by an exudation into the peridental membrane which 
destroyed its vitality and led to the formation of pus and all the other 
symptoms and pathological conditions characteristic of the disease. 
A commission composed of MM. Despres, Delens, and Magitot was 
appointed by the Societe de Chirurgie of Paris to consider the state- 
ments of Dr. Serran. In this report 1 they denied the gingival origin of 
the disease, and stated their belief that the periosteal membrane and 
the cementum were the primary anatomical seat of the lesion; that the 
succession of morbid phenomena completely precluded the idea of an 
initial gingivitis; that the disease begins without any trace of conges- 
tion of the gums; that after its formation the pus burrows toward the 
gingival border, which it detaches — without, however, for a time 

1 Bulletins et Memoirs de la Societe de Chirurgie, tome vi, p. 411. 
30 



466 PYORRHEA ALVEOLARIS 

destroying its normal aspect; that only after considerable augmentation 
of the flow of pus and the loosening of the teeth do the gums become 
implicated ; that the disease had nothing in common with the hypothesis 
of a gingival malady, and that it is most frequently a manifestation of 
a general state, or a diathesis. 

These were the views entertained and published by French surgeons 
on the nature of " pyorrhea alveolaris" about the period when the dis- 
ease began to receive consideration from American dentists. Although 
pyorrhea alveolaris had long been recognized in the United States and 
various observations regarding its pathology and treatment had been 
published, it was not until Dr. John W. Riggs, of Hartford, Conn., in 
October, 1875, read a paper before the American Academy of Dental 
Surgery, entitled ( ' Suppurative Inflammation of the Gums and Absorp- 
tion of the Gums and Alveolar Processes/' that the disease began to 
attract the attention its gravity merited. Notwithstanding the views 
entertained by Magitot and others regarding the constitutional character 
of the disease, Dr. Riggs in his communication 1 emphatically denied 
that the disease is an affection of the bone or of the gums, or that it is 
hereditary or constitutional, but, on the contrary, that it is the roughened 
teeth themselves, in consequence of the accretions from whatever source 
derived, which are the exciting cause of the inflammation; that it is 
purely local in origin, the result of concretions near and under the free 
margins of the gums, the removal of which even in the third stage is 
followed by cure. 

In 1877 Dr. F. H. Rehwinkel 2 entered his protest against the theory 
of the local origin of the disease, and endeavored to prove that it not 
only may but does exist independently of foreign deposit and must 
depend on other than merely local causes, and that it is an hereditary 
and constitutional disease. 

Dr. L. C. Ingersoll, in 1881, published a paper entitled "Sanguinary 
Calculus/' 3 in which it was stated that the persistent flow and discharge 
of pus along the side of the tooth was caused by an inflammation and 
ulceration at or near the apex of the root; as a result of which molecular 
death the liquor sanguinis escaped from the bloodvessels into the 
surrounding tissues and became disorganized, the lime salts crystal- 
lized on the surface of the roots, and formed the deposit which from its 
origin he designated " sanguinary calculus." This deposition he regarded 
as entirely distinct from salivary calculus, and as derived from the 

1 Pennsylvania Journal of Dental Science, vol. iii, p. 99. 

2 Report of the Committee on Pathology and Surgery, Trans. American Dental 
Association, 1877, p. 96. 

3 Ohio State Journal of Dental Science, vol. i, p. 189. 



HISTORY 467 

blood — the result of inflammatory action and not its cause. In other 
words, he held that pyorrhea is a local disease but beginning centrally; 
that is, at or near the apex of the root. 

In 1882 Dr. A. Witzel read a paper before the German Society of 
Dentists, 1 in which it was asserted that the primary pathological change 
was an inflammation and caries of the alveolar border followed by a 
deposit just beneath the free margins of the gums, which became re- 
tracted and reverted. The entrance of micro-organisms into this carious 
region developed pus which became more or less infectious. In conse- 
quence he termed the disease "infectious alveolitis." He regarded the 
disease as a primary local alveolitis, having no constitutional relations 
whatever, a molecular necrosis of the alveoli or caries of the dental 
sockets produced by septic irritation of the medulla of the bone. 

In 1886 Dr. G. V. Black prepared probably the most exhaustive 
paper in print in the United States, wherein pyorrhea alveolaris is 
treated as a local disturbance. 2 Calcic inflammation and phagedenic 
pericementitis are the terms he employs to indicate its character. 
Although he believes it to be wholly local, he thinks a serumal or san- 
guinary deposit may be closely allied with its origin. He describes it 
as a destructive inflammation of the pericemental membrane, distinct 
from other inflammations of this tissue, although having many features 
in common with them. The disease, he estimates, is essentially one 
of the peiidental membrane rather than of the alveolus, although the 
destruction of these two structures is so nearly synchronous that it is 
difficult to say which has gone first. 

In 1886 Dr. W. J. Reese read a paper before the Louisiana State 
Dental Association on "Uremia and its Effect on the Teeth," 3 in which 
the chemical, physiological, and pathological relations of uric acid to the 
general nutrition were discussed. In this communication Dr. Reese 
expressed the opinion that the inflammation of the pericemental mem- 
brane, followed by suppuration and disorganization when in contact with 
the secretions of the mouth, is caused by the deposition of uric acid 
derived from the blood; that the disease should be termed "phagedena 
pericementi;" that "pyorrhea alveolaris" is a misnomer. He also stated 
that while the tophus on the roots of the teeth is the usual concom- 
itant of uric acid, it is not necessarily so, but that absorption of the 
pericemental membrane may take place without any deposit. Although 



1 Vierteljahresschrift fur Zahnheilkunde, 1882; British Journal of Dental Science, 
vol. xxv, p. 153. 

2 Diseases of the Peridental Membrane having their Beginning at the Margin of 
the Gum, American System of Dentistry, vol. v, p. 953. 

3 Dental Cosmos, vol. xxv, p. 550. 



468 PYORRHEA ALVEOLARIS 

a local treatment was advocated, he stated that without systemic or 
constitutional treatment the return of the trouble may be expected. 

Dr. John S. Marshall, in 1891, expressed his conviction that pyor- 
rhea has a constitutional origin and is closely allied to the rheumatic 
or gouty diathesis; "that the deposition of the concretions upon the 
roots of the teeth in those localities not easily reached by the saliva, or 
in which the presence of the saliva would be an impossibility, is due 
to the causes which produce the chalky formations found in the joints 
and fibrous tissues of gouty and rheumatic individuals." 1 

C. N. Peirce, in a series of papers published during 1892-94-95, 2 pre- 
sented a number of clinical and pathological facts which in their totality 
it was believed established a kinship between pyorrhea alveolaris or 
hematogenic calcic pericementitis and the constitutional state familiarly 
known as the gouty or uric acid diathesis. 

Recent literature by American writers has dealt largely with the 
problem of the etiology of the disease in question and has been princi- 
pally concerned in determining whether it is of constitutional origin or 
of local origin, or of both. Of the more important recent writings on 
the subject may be mentioned those of Drs. E. T. Darby, H. H. Bur- 
chard, G. V. Black, E. S. Talbot, M. L. Rhein, E. C. Kirk, James 
Truman, Junius E. Cravens, Louis Jack, R. R. Andrews, and R. 
Ottolengui. 

Terminology. — No disease in the whole domain of surgery has received 
so many and such diverse names as the one under consideration. Each 
succeeding title was an attempt at the production of a comprehensive 
descriptive designation of the disease, but when it is recognized that 
the essential nature of the pathological processes involved is, even 
now, not fully made out, it is evident that the many names simply 
represent as many diverse views and can therefore have no permanency, 
nor do they, indeed, deserve any. 

The following is a fairly complete list of the synonyms of the dis- 
order: Suppuration conjointe, pyorrhee inter-alveolo-dentaire, gingi- 
vitis expulsiva, bsteo-periostite-alveolo-dentaire, pyorrhea alveolo, 
cemento-periostitis, infectioso-alveolitis, pyorrhea alveolaris, calcic 
inflammation, phagedenic pericementitis, Riggs' disease, interstitial 
gingivitis, hematogenic calcic pericementitis, blennorrhea alveolaris, 
gouty pericementitis. 

It should be noted that pyorrhea alveolaris (flowing of pus 
from the alveolus) is a generic term carelessly used to designate a 

1 The Rheumatic and Gouty Diathesis, with its Manifestations in the Peridental 
Membrane, Transactions American Medical Association, 1891. 

2 International Dental Journal, vols, xiii, xv. and xvi. 



GENERAL CONSIDERATIONS 469 

group of disorders all of which result in loss of the teeth by destruc- 
tion of their retentive tissues; also, that this loss may and often 
does occur without the obvious production of pus as an attendant 
symptom. The term pyorrhea alveolaris is, therefore, inaccurate as 
descriptive of the disease and unscientific except as it is indicative 
of a symptom common to several disorders; but, inasmuch as the desig- 
nation is in common and general use, and still further because the 
etiology of the several gingival disorders so described still remains to 
be scientifically demonstrated, it will be more convenient to retain 
"pyorrhea alveolaris' ' as a general designation until a more accurate 
terminology based upon the known etiology and pathology of these 
destructive inflammatory alveolar disorders becomes possible as the 
result of further study and investigation. It should, therefore, be under- 
stood that the term pyorrhea alveolaris is used throughout this chapter 
in its general sense as applied to the group of disorders having the 
clinical characteristics specified under "Definition" in the opening 
paragraph of this chapter. 

General Considerations. — One fact is clearly evident in all forms of 
pyorrhea alveolaris, viz., that it is an inflammatory disorder. It may 
be acute and violent, running a comparatively short course, or it may 
be chronic over a long period; the evidences of inflammatory activity 
may be so slight as to escape other than critical notice, yet the morbid 
process in its clinical manifestations and in its destructive results falls 
strictly within the limitations prescribed by the modern definitions of 
inflammatory action. 

Inflammation, as defined by Adami, 1 is " the succession of changes 
which constitute the local effort at adaptation to the changes initiated 
by actual or referred injury to a part; or, in short, the local adaptive 
changes resulting from actual or referred injury." " Anything which causes 
local injury to the tissues is a cause for inflammation, be it a mechani- 
cal trauma, a physical insult, as by heat, cold, or electricity, a disturb- 
ance brought about by altered metabolism and abnormal internal 
secretions or by bacterial or microbic invasion and growth. This last 
is the commonest cause of acute reaction, and differs from the physical 
and mechanical causes (although not from metabolic disturbances) in 
that, as a cause, it is not of momentary duration, but continued. It is 
not the mere physical entry of microbes into the tissues that induces 
inflammation, but the liberation by them of their products in growth 
or disintegration. And so long as those products are being liberated, 
for so long is the cause in action. It differs from the metabolic causes 

1 Principles of Pathology, vol. i, p. 377. 



470 PYORRHEA ALVEOLARIS 

in that the latter induce tissue irritation of a milder grade, and so do 
not induce acute but rather chronic reactions." 

Viewed as an inflammatory process we have, then, in the study of 
pyorrhea to regard its clinical or objective phenomena as reactions of 
the retentive tissues of the teeth toward injuries inflicted by mechanical 
trauma, physical irritants, altered metabolism, the toxic effects of 
altered secretions, or by the toxic products of microbic or bacterial 
invasion. Any of these agencies, severally or collectively, may induce 
such changes in the retentive structures as will lead to their molecular 
necrosis and the ultimate exfoliation of the teeth, the process consti- 
tuting comprehensively what we know as pyorrhea alveolaris. 

Pyorrhea alveolaris is a condition of disease as opposed to health 
of the tissues concerned in the fixation or retention of the teeth in the 
alveolar borders. It is a disturbance of the normal health of these 
tissues. 

The condition which we speak of as health may be defined in its 
ideal sense as that condition or state which is the resultant of the har- 
monious concurrent or interaction of all those factors necessary to the 
normal functioning of a tissue or organism, or, shortly, health is a state 
of metabolic or physiological equilibrium. Any definition of health as 
applied to an organism or to a tissue must necessarily be imperfect in 
that it cannot, in the nature of the case, be absolute, for the reason that 
the functioning of a tissue or its cells, as well as of the entire organism, 
is dominated by the factor of vitality or life, a phenomenon which in 
the present state of human knowledge eludes definition. As a meta- 
physical formula the working definition of life proposed by Mr. Herbert 
Spencer affords assistance in arriving at a conception of the meaning 
of that ideal state of physiological functioning which we speak of as 
health. Spencer defines life as "the continuous adaptation of internal 
relations to external relations." It will be seen that this conception 
includes, as all attempts at the definition of vital action must include, 
a recognition of the variability of vitality. Health, then, which is a 
condition of life dependent upon physiological balance or harmony of 
metabolic activity (internal conditions) in relation to environment 
(external conditions), can never be regarded as a condition or state 
of stability, but rather as a condition of continuous variability. The 
metabolic equilibrium of health is therefore to be understood not as 
a fixed, but rather as an unstable or moving equilibrium. 

The equilibrium of health finds certain analogies in that of the bicycle 
in action. The energy of the rider imparted to the mechanism causes it 
to maintain its balance and to advance along a course which approaches 



ETIOLOGY 471 

a straight line, this approach being directly proportionate to the energy 
which the machine receives. If the energy falls below that required to 
maintain equilibrium, the machine drops to the ground. External 
agencies, such as inequalities in the road bed, obstructions to the smooth 
revolution of the wheels, deviations of the course involving ascent of 
surface inclines, high winds, these or any of the numerous environing 
conditions which may beset the cyclist, demand recurrent accesses of 
energy in order to maintain equilibrium of the machine and propel it 
upon its course. Or if, from fatigue or other internal causes, the cyclist 
becomes incapable of delivering to his wheel the necessary potential, 
then in that case also the machine falls to the ground. 

The study of disease action as it is expressed in pyorrheal conditions 
of the retentive tissues of the teeth is a study of the adaptive reactions 
of these tissues to those agencies which tend to destroy their normal 
physiological equilibrium, the phenomena attending the effort of the 
forces of the tissues to oppose injuries, be they mechanical trauma, 
physical or chemical. 

It should be clearly understood that no sharp dividing line can be 
drawn between the ideal state which we call health and those departures 
from it which we call disease. No two individuals are alike in any 
respect, for which reason the standards of physiological equilibrium, 
or of health, differ as individuals differ. Nor in the same individual 
are the physiological activities continuously in normal equilibrium. 
Variations from the normal brought about by the play of environing 
conditions are constantly producing departures from normal states as 
a necessary result of the process of living. These departures from nor- 
mality vary by insensible 5 degrees from little to greater, so that it is 
impossible to draw a sharp line of demarcation and define at what 
point we cease to deal with the physiological state and are confronted 
with the pathological. This general fact applies not only to the organ- 
ism as a whole, but to its component tissues as well, hence in the study 
of the group of gingival disorders here considered as pyorrhea alveolaris 
we are confronted not only with a variety of lesions, but an infinite 
gradation in intensity of the phenomena involved. 



ETIOLOGY 

The study of pathological lesions must have its basis in a knowledge 
of the anatomical structure of the tissues involved, hence an under- 
standing of the nature of the destructive processes which produce 



472 PYORRHEA ALVEOLARIS 

necrosis of the retentive tissues of the teeth, and their final exfoliation 
can only be intelligently arrived at after a comprehension of the structure 
and function of the retentive tissues of the teeth has been acquired. 

Broadly speaking, the tissues concerned in the inflammatory processes 
under consideration, and collectively referred to as the retentive tissues 
of the teeth, are the bony alveolar structures with their overlying gum 
tissues and the ligamentous tissue by which the teeth are attached to 
their alveoli, known as the pericemental or peridental membrane. These 
with their vascular and nervous supply are all involved in the various 
pyorrheal affections, while in certain aspects of the disorder a group 
of peculiar structures embedded in the pericementum, probably cellular 
remnants of the embryonal structure known as the epithelial sheath 
of Hertwig, described by G. V. Black as lymphatic glands, 1 play a most 
important part. 2 

External Factors. — As a whole, the teeth and their associated tissues 
are fixed in an environment which is the source of a variety of irritative 
factors, many of which are capable of exerting harmful influences and, 
among other injurious results, of giving rise to the destructive phenomena 
of pyorrhea alveolaris. Since Antoni van Leeuwenhoek, the linen- 
draper of Amsterdam, in 1683, announced to the Royal Society of 
London his discovery of " animalcule, " which he had found in the 
"materia alba/' or white deposit scraped from the surfaces of his own 
teeth, the investigation of the bacterial forms found in the human 
mouth has progressed until at the present time it is a well-established 
fact that the human mouth is the breeding ground or incubator for 
an extensive variety and infinite number of bacterial forms, many of 
which are the known exciters of disease action" both locally in the mouth 
itself and in the more remote organs and tissues of the body. 

No human mouth is ever free from bacterial contamination at any 
time from birth to death, and no method has as yet been devised by 
which complete sterilization of the oral cavity may be safely accomplished. 
Nevertheless, very many mouths are free from any evidence of bacterial 
invasion and consequent inflammatory reaction of the tissues, notwith- 
standing the fact that even in such mouths the presence of pathogenic 
bacteria may be abundantly demonstrated. Infection of the oral tissues 
in such cases is prevented by the internal resistive powers of the dental 
and oral tissues, as infection of the other tissues of the healthy body is 

1 A Studv of the Histological Characters of the Periosteum and Peridental Mem- 
brane, Chicago, 1887, p. 90. The Fibers and Glands of the Peridental Membrane, 
Dental Cosmos, 1899, vol. xli, p. 101. 

2 For a detailed description of the retentive structures of the teeth the reader is 
referred to pp. 94 to 115 of Chapter IT. 



ETIOLOGY _ 473 

prevented by the adaptive agencies of the vital mechanism. The sum 
total of the resistive forces against the invasion of pathogenic bacterial 
elements is termed immunity, a state which to a large degree is one of 
the conditions of normal health, in which instance it is designated as 
natural immunity, or, within certain limits, the condition may be 
artificially produced, and it is then designated as acquired immunity. 

It will be seen from the foregoing that bacterial invasion of the 
tissues and consequent inflammatory reaction in them depends upon the 
overpowering of the internal resistive forces of the tissues by patho- 
genic bacteria endowed with a disease-producing potential of relatively 
higher intensity than that of the resistive power of the tissues. Wherever 
bacterial invasion and consequent inflammatory reaction in the tissue 
results, it means that the defensive powers of the tissue have been over- 
come by the invading organism, the equilibrium of tissue health has been 
destroyed,' and a condition of disease has been established. 

The causes of pyorrheal inflammation are rarely, if ever, simple in 
character in the sense that they are the direct and unaided effects of 
specific infection in a normally healthy tissue. Various contributory 
or predisposing factors are usually concerned in the production of these 
gingival and alveolar inflammations. The factors which contribute to 
the bacterial invasion of the gingival tissues may be broadly classified 
as external and internal. 

Among external causes may be included mechanical injury to the 
tissues involved. Any agencies which injuie the gingival tissues to the 
extent of creating in them a traumatic lesion may serve as a predis- 
posing cause of pyorrhea alveolaris. Injury to the tissues, depending 
upon its degree and seriousness, will produce either cell death with total 
loss of resistance, or if not cell death, then disturbance of cell function, 
with greatly diminished resistance to bacterial invasion. 

Injudicious application of ligatures or clamps in adjusting the rubber 
dam, similar maltreatment of the pericemental membrane at its cervical 
attachment by the improper application of band and other forms of 
matrices, and, above all, the physical insult to the pericementum result- 
ing from an unskilfully fitted artificial crown, especially of the banded 
type, are fruitful sources of traumatic injury which are definitely known 
to be predisposing causes of pyorrhea alveolaris. 

Tartar as a Predisposing Cause. — Among the traumatic predisposing 
causes of pyorrhea alveolaris, none is so frequent or so generally notice- 
able as the injury to the retentive tissues of the teeth produced by 
accumulation of salivary calculus, or tartar. Salivary calculus is here 
classified as a traumatic irritant predisposing to pyorrhea alveolaris, 



474 PYORRHEA ALVEOLARIS 

for the reason that the encroachment of growing accumulations of tartar 
is not alone sufficient to account for the inflammatory reaction which 
accompanies it, and further, because the pus production associated with 
this form of pyorrhea is necessarily a result of bacterial infection. The 
exact nature of the process of tartar formation has not as yet been made 
out with definite clearness. It is known in general that salivary calculus 
or tartar is composed of calcium phosphate and carbonate with occa- 
sionally other allied salts formed into a concretion by the mucinous 
elements of the saliva, and that it contains entangled in its structure 
the bodies of a variety of bacterial forms. The earthy salts which 
enter into the composition of salivary calculus are derived from the 
saliva, where, under normal conditions of health, they are retained in 
solution, but in certain unknown nutritional changes which bring about 
alterations in the composition of the mixed saliva, a portion of the 
dissolved calcium salts undergoes precipitation upon surfaces of the 
teeth protected from the friction of the tongue, lips, and cheek tissues, 
these deposits undergoing an incremental growth until in some instances 
they attain a relatively enormous size. 

Deposits of tartar upon the teeth present a large variety of forms 
and marked differences in position and physical characteristics, but 
whenever the deposit impinges upon the retentive tissues of the teeth 
it acts as a traumatic irritant, which interferes with the nutrition of the 
soft tissues, decreasing their normal resistive power, and by so doing 
renders them susceptible to invasion by pathogenic organisms, thus 
setting up inflammatory reactions, among which are certain forms of 
pyorrhea alveolaris. There is nothing in the composition of salivary 
tartar, as such, that can cause chemical irritation. Its action is dis- 
tinctly and simply mechanical or traumatic, and as a causative factor 
in the production of marginal inflammation it must therefore be classed 
as among the predisposing causes. The exciting or immediate cause of 
the inflammatory reaction is bacterial infection of the tissue injured by 
the tartar deposit. 

Deposits of tartar are classified, with respect to their origin, as salivary 
calculus and as serumal or sanguinary calculus, according as the deposit 
has been derived from the saliva or from the blood plasma respectively. 

While it has been definitely determined that deposits of calculus 
occur upon the roots of teeth in which the possibility of access of saliva 
has been excluded, it has not by any means been clearly shown that the 
thin scaly deposits of tartar found upon the roots of teeth in cases 
of pyorrhea alveolaris nor the thin scale-like ring of tartar found 
encircling the necks of teeth below the gingival margin in similar cases, 



ETIOLOGY 



475 



owe their origin to the blood plasma and are, therefore, properly 
designated serumal tartar, as such deposits are ordinarily classed, for 
the reason that in both these instances there is more or less free access 
of saliva to the region of the deposit, and no tartar deposit can with 
accuracy be described as serumal tartar unless absolute exclusion of 
saliva from the region of the deposit is demonstrable. 



Fig. 535 




Fig. 526 



S.L.C 




A, maxillary sinus; B, duct of Steno; C, 
parotid calculus; E, submaxillary gland. 



C, calculus; S.L.C, sublingual cavity 
S.L.G.L., sublingual gland. 



The mere physical differences observed in tartar deposits are not 
in themselves sufficient to definitely determine either the salivary or 
the blood origin of the deposit respectively. Differences in the physical 
characteristics of tartar deposits are due, among other things, to varia- 
tions in chemical composition and to the rate of growth or formation 
of the deposits, and these factors are in their turn dependent upon the 
composition of the fluids from which the deposits or precipitation of 
earthy salts takes place, while the composition of these fluids, finally, 
is dependent upon the nutritional state of the individual upon whose 
teeth the deposits are formed. 

In certain individuals the accumulation of tartar as a deposit from 
the saliva is constant and relatively rapid. In such cases the accumu- 
lation is greatest upon tooth surfaces which face the orifices of the ducts 
of the parotids, the so-called ducts of Steno, and upon the lingual 



476 



PYORRHEA ALVEOLARIS 



Fig. 537 



surfaces of the lower incisors, which are opposite the orifices of Wharton's 
ducts (Figs. 535 and 536). In these localities precipitation of salivary 
tartar occurs most frequently, and in many instances the deposits grow 
to enormous size (Figs. 537 and 538). That the deposit is salivary in 

its origin is shown by the commonly ob- 
served fact that it will take place upon 
an artificial denture as readily as upon 
the necks of the natural teeth (Fig. 539). 
The salivary deposit may be small in 
amount and relatively slow in accumu- 
lating, or it may, on the contrary, be large 
in amount and accumulate rapidly; and 
there also appears to be a fairly definite 
correspondence between the density and 






Fig. 538 








' «b_ 










jiiife 


jdP 






vv*- : : 


jgHKrjR- * 


i m 


■ 


M 


r 


^V- f **V ;-- 


S jf: 


f 




4 


2?." \ V V' -. * v '^ 


*!?", . *IWW^ 


~Nc/i# 


:*mm 



Specimens of parotid tartar; actual size. 
Fig. 539 





WtpfSKnP 8 




t **» IB 


, ;:':'■.■.-■.;:•; 










.^t>~i 




^- r.-3p 
















. 




^^ 


v'^~ 


HJl i HMVnlHHMKBiHR 


K^t&L 


-ISI^^II 






^m 




'" ;"»*gg 


v If 




'^jBw 






. 




£***. 


..-.-- 



Partial denture clasped to first and second molars, which have been lost by deposition of 

parotid tartar. 



ETIOLOGY 

Fig. 540 



477 




Fig. 


541 








IP f 


marf 






^^PP5«^ i J .^" 




■pr< 








/ / ?/ 






*#" 




B )9> 



Fig. 542 




478 



PYORRHEA ALVEOLARIS 



hardness of the deposit and its rate of formation, the density being 
in inverse ratio to the rapidity of its formation. Figs. 540, 541, 542, 



Fig. 54a 




w\ 


■ 






' 




y I 




^i-py *- \ 




fl^Btj v< ' ^HBPIj 





Fig. 544 




Fig. 54^ 




543, 544, and 545 show various commonly observed forms of salivary 
tartar deposition. Another important factor is, however, concerned 



ETIOLOGY 479 

in tartar formation, one which has much to do with its physical 
characteristics and incidentally with its rate of formation, and that 
is the relative quantity of mucin or other colloids in the medium 
from which the tartar is precipitated. 

Nature of Tartar Composition. — In 1858 Mr. Rainey, of London, made 
the important discovery 1 that when certain earthy salts are precipitated 
in a medium containing a colloidal substance in solution, the resulting 
precipitate was profoundly modified in the form of its ultimate particles 
which instead of being crystalline in character were in the form of minute 
spheroidal masses, and that as the precipitation progressed the sphe- 
roidal masses increased in diameter so that adjoining masses grew into 
contact, and, by accretion of new material, they coalesced until finally 
the coalescence of a large number of individual spherules gave rise 
to the formation of mulberry-like masses. Mr. Rainey's experiments 
were made with gum arabic as the colloidal material in the menstruum 
from which the precipitation of earthy material was made, and micro- 
scopic examination of the spheroidal concretions thus produced showed 
a laminated or onion-like structure quite analogous to that found in the 
shells of hen's or bird's eggs, the shells of molluscs, calcareous concre- 
tions in the urine of the horse, etc. Contemporaneously with Rainey's 
investigations, Professor Harting, 2 of Utrecht, pursued the same line of 
inquiry, and not only confirmed the observations of Rainey, but greatly 
extended his results by showing that with animal colloids, such as egg 
albumin, blood serum, or a solution of gelatin, a much greater variety 
of forms may be produced, many of them closely resembling concretions 
only found in the animal body. Professor Harting brought out the 
further fact that the resistance of these spheroidal concretions to the 
solvent action of acids was greater than that of the precipitates formed 
from the same material in the absence of colloids, and that after treat- 
ment by acids until all visible particles of calcareous matter were dis- 
solved out there remained a basic substance or matrix upon which, 
although it still retained its original form, the acid apparently had no 
further action, and to this residue of insoluble material he gave the 
name "caleoglobulin;" he also made the further important observa- 
tion that when various coloring matters, such as madder, logwood, 

1 See his treatise, On the Mode of Formation of the Shells of Animals, of Bone, 
and of Several other Structures by a Process of Molecular Coalescence Demonstrable 
in Certain Artificially Formed Products, 1858, and his Further Experiments and 
Observations, in Quarterly Journal of Microscopical Science, 1861, n. s., vol. i, 
p . ^o . 

2 See Professor Harting's Recherches de Morphologie synthetique sur la pro- 
duction artincielle de quelques Formations Calcaires Inorganiques, publiees par 
l'Academie Royale Neerlandaise des Sciences, Amsterdam, 1872, and Quarterly 
Journal of Microscopical Science, vol. xii, p. 118. 



480 PYORRHEA ALVEOLARIS 

or carmin, were added to the solution in which the precipitation was 
taking place the concretions took on the hue of the dye employed, ?'. e., 
that they were readily susceptible of pigmentation. The same line of 
inquiry was confirmed and further carried out by Dr. W. M. Ord 1 with 
reference to the formation of urinary and other calculi. 

The data derived from the researches of Rainey, Harting, and Ord 
have served to explain the chemical principles involved not only in 
the various phenomena of normal calcification of the several hard or 
calcified tissues of the animal body, but also of the numerous patho- 
logical concretions found associated with disease processes, such as 
vesical, renal, and biliary calculi, the calcification of the debris of 
suppurative processes in various tissues and organs, and the calculous 
deposits upon the teeth. The essential factor in all of these processes 
is the precipitation of a relatively insoluble earthy substance in a 
medium containing colloid material, such as protoplasm, albumin, 
mucin, casein, and allied organic substances, which unites with the 
inorganic element to form compounds having the physical character- 
istics of calcoglobulin, and likewise its habit of forming spheroidal 
masses that grow by accretion and coalescence into irregular mulberry- 
like concretions. 

The mixed saliva contains a variable amount of calcium phosphate 
in solution, but the exact nature of the dissolved phosphate has not been 
definitely determined. It is, however, known that tricalcic phosphate, 
Ca 3 (P0 4 ) 2 , is soluble in nearly all acids and is soluble even in carbonic 
acid, a fact determined by the English chemist, W. H. Pepys, Jr., as 
early as 1803. 2 

As the saliva contains carbon dioxid in solution, it has been assumed, 
with some justification, that the escape of the carbon dioxid which was 
the solvent of the calcium carbonate and tricalcic phosphate, causes a 
precipitation of those salts in the presence of the colloid mucin, in 
combination with which it deposits as tartar upon the teeth. While 
the foregoing may serve as an explanation of one method of salivary 
tartar formation, an almost unlimited variety of conditions are prob- 
able which involve the fundamental principle of precipitation of 
tricalcic phosphate from solution, and when this precipitation takes 
place in any colloidal medium the result is a calcic concretion modi- 
fied in its physical characteristics by the conditions under which the 
precipitation and concretion occurred. 

1 On the Influence of Colloids upon Crystalline Forms and Cohesion, London, 
1879. 

2 The Natural History of Diseases of the Human Teexn, by Joseph Fox, London, 
1803, p. 94. 



ETIOLOGY 4S1 

H. H. Burchard 1 proposed an explanation for the formation of 
salivary tartar deserving of consideration, viz., that inasmuch as 
fermentative processes in the oral cavity give rise to acids, and par- 
ticularly lactic acid, these acids cause precipitation of the mucin of the 
saliva as a coagulum which entangles in its structure calcic phosphate 
and carbonate, and this mass by gradual condensation increases 
in density to the extent of forming the coherent deposit known as 
tartar. 

It is also known that in many individuals in whose mouths proteid 
substances are undergoing decomposition the exhaled breath contains 
appreciable quantities of ammonia which may be recognized by 
Xessler's reaction or by the murexid test. It is further known that 
ammonia will cause a precipitation of calcium phosphate from its acid 
solutions, as calcium ammonium phosphate, or when magnesium is 
present ammonium magnesium phosphate, so-called triple phosphate, 
is also precipitated, and this latter salt has been identified as one of 
the constituents of certain varieties of tartar. 

As the earthy phosphatic salts of the saliva must in the nature of 
the case be retained in a state of solution in the saliva by virtue of 
some form of acid combination either as simply dissolved in carbon 
dioxid or in the form of acid calcic phosphate, a soluble salt, then 
any agency which would eliminate the acid element, e. g., the escape 
by evaporation of the contained carbonic acid, or again the presence 
of ammonia in the breath, or the introduction of a basic substance into 
the saliva, would lead to precipitation, as already shown. 

An interesting example of the production of tartar by neutralization 
of the acid solvent element of the salivary phosphates is furnished by 
the tartar deposits found upon the teeth of the betel-nut chewers of 
the Malay Archipelago, India, and Indo-China. The habit of betel- 
nut chewing is practically universal among all classes in the regions 
mentioned. 

The masticatory bolus is prepared by wrapping slices of betel-nut, 
the fruit of the areca palm, in a leaf of the piper betel, or Pinang, 
a climbing shrub cultivated in the East to a prodigious extent 
for the purpose. The slices of areca nut are first sprinkled with a 
little lime to develop the desired flavor. The chewing of the bolus 
causes a deep red staining of the teeth and the rapid accumulation of 
large, dense deposits of tartar which at first are red, then finally become 
a dark chestnut brown or black. The encroachment of the tartar is 

1 See Origin of Salivary Calculus, by Henry H. Burchard, Dental Cosmos, 1895, 
vol. xxvii, p. 821. Also Varieties of Dental Calculi, by the same author, Dental 
Cosmos, 1898, vol. xl, p. 1. 
31 



482 PYORRHEA ALVEOLARIS 

Fig. 54G Fig. 547 



«8 9 





Lower incisor almost completely encrusted 
with betel tartar. 

Fig. 548 





H 


i 


Eg 


1 




Li 





Lower canine with thick incrustation of 
betel tartar. 



Fig. 549 





Lower bicuspid with extensive deposit of betel tartar. Lower canine covered with betel tartar. 



ETIOLOGY 



483 



so rapid and destructive that habitues frequently become toothless at 
twenty-five years of age. Figs. 546. 547, 548, and 549 show examples of 



Fig. ,550 








Fig 


551 




m 








- 1 |^^ 


\$$ jk! 


> 








tF,J 










vli 










■>vSi)|rej 




v ^H| 







Upper and lower incisors lost from deposit of betel tartar. 



individual teeth lost from betel-nut tartar, and Figs. 550 and 551 the 
upper and lower incisor teeth of an individual similarly lost, but which 



484 PYORRHEA ALVEOLARIS 

during the loosening stage had been ligatured with fine brass wire by 
a native dentist as a temporary support, the whole group of incisors 
being later exfoliated en masse. It' is highly probable that the use of 
the lime in connection with the betel-nut furnishes the necessary 
basic element to throw down the earthy phosphates of the saliva as 
tricalcic phosphate in the form of tartar, just as the ammonia of the 
breath performs an analogous function in the precipitation of tricalcic 
phosphate and triple phosphate as elements of tartar formation. 

Subgingival Tartar. — The chemical principles governing the precipi- 
tation of earthy phosphates and carbonates directly from the saliva in 
the production of true salivary tartar govern also the production of the 
girdle-like concretions that are found encircling the teeth at and below 
the anatomical neck and beneath the gum margin. Deposits of sub- 
gingival tartar differ markedly in their physical characteristics from true 
salivary tartar, being denser in structure, slower of formation, darker 
in color, and more firmly adherent to the tooth. These differences are 
most probably due to the fact that they are deposited in a region rich 
in mucin, which exudes freely from the mucinous acini embedded in 
the marginal gum tissue, and possibly also from the gland-like structure 
encircling the alveolar border known as the gland of Serres. The 
subgingival deposits are always accompanied, and, indeed, are usually 
preceded, by a marginal catarrhal inflammation, which induces an 
exudation of mucus rich in colloidal material, which is the binding 
material of the tartar deposit, giving to it the resistant quality and 
hardness characteristic of the deposits found in these locations. The 
peculiar dark brown or greenish coloration is derived from the hemo- 
globin exuded from the inflamed marginal gum tissue, which, in contact 
with the hydrogen and ammonium sulphid, which are the end products 
of putrefactive decomposition of proteids, becomes sulfomethemo- 
globin, the same compound which produces the dirty brown or greenish 
discoloration so often found at the necks of teeth in cases of marginal 
gingivitis. 

While there are doubtless a variety of conditions which lead to pre- 
cipitation of the earthy salts of the saliva in combination with the 
colloidal mucin, thus producing deposits of infinite variety in physical 
characteristics, the deposits, generally speaking, when first formed, are 
soft and friable, and are then readily removed by appropriate instru- 
mentation; but they tend to grow denser and harder as condensation 
of the mass in course of time proceeds, until in some instances they 
appear to be as resistant to cutting instruments as the cementum of 
the tooth root to which thev are attached. On the other hand, the 



ETIOLOGY 4<So 

larger salivary calculi of rapid growth are generally friable and chalky 
in texture, showing a relatively less amount of organic colloidal binding 
material in their structure, the precipitation having occurred in a saliva 
containing a deficiency of the mucinous element. 

The extent of the inflammatory reaction induced by the impingement 
of salivary calculus upon the gingival tissues varies between wide ex- 
tremes from a slight superficial gingivitis to an active, necrotic, suppura- 
tive inflammation which is a true pyorrhea alveolaris. In cases where 
the resistive forces of the gingival and alveolar tissues are of normal 
standard the destructive process initiated by the tartar deposit is 
superficial and ulcerative in type. On the surface of the tissue imme- 
diately below the surface of contact of the deposit an ulcerative destruc- 
tion of the tissue elements takes place, the area of engorgement, recog- 
nizable as a red line, is quite shallow, with normal healthy tissue imme- 
diately below it. When the impinging mass of tartar is carefully removed 
and the contact surface tissue is examined, it will show a denuded 
ulcerating appearance with frequently the evidences of necrotic tissue 
debris and pus distributed over the exposed area. If the tartar deposit 
has been a sufficiently large one, its surface of contact with the soft 
tissue will frequently show distinctive evidences of pus formation, 
the exudate being of a characteristic dark greenish or yellowish-brown 
color. Where the deposit is permitted to remain and to increase in size, 
the ulcerative process continues until the retentive structures of the 
involved teeth are completely destroyed and the teeth are exfoliated. 
The characteristic distinction between this type of destructive inflam- 
matory disease of the retentive tissues of the teeth due to deposits of 
salivary tartar and those of the graver and more intractable class of 
pyorrheal disorders of the same structures is the superficial and ulcerative 
character of the inflammatory lesion in the former. The injury caused 
by the impingement of the tartar deposit has damaged the subjacent 
tissue only upon its surface, consequently the bacterial invasion of the 
damaged tissue has been little more than superficial; the defensive 
forces of the underlying healthy tissue limit the bacterial invasion 
to the layer of cells which were functionally disabled as the result of 
encroachment by the tartar deposit. 

Where the inflammatory process has not destroyed the mechanical 
efficiency of the attachment of the tooth to its alveolus, the disease 
condition is readilv curable bv the removal of its cause. 



486 PYORRHEA ALVEOLAR! S 



TREATMENT 

The operation of removing tartar deposits is commonly described 
as "scaling the teeth/' and the instruments employed specifically for 
that purpose are designated as scalers. 

Instruments. — For the removal of large concretions of tartar a few 
simple forms of scalers are sufficient, as indicated in Chapter IV, Fig. 
100, but for the removal of smaller deposits, especially those situated 
below the anatomical neck of the tooth, an outfit of more delicately 
constructed instruments, a sufficient number of them having curvatures 
of shank so contrived as to admit of ready application to all the surfaces 
of all of the teeth, should form part of the armamentarium of every 
practitioner who attempts to effectively perform the operation of scaling. 

Two types of effective cutting edge should be available in connection 
with the several forms of instrument shank comprising the operator's 
outfit of scalers, viz., the type which is used for a pushing cut and the 
type used for a pull or drawing cut. Certain scaler points may combine 
both possibilities: for example, when the blade of the scaler is turned 
to an exact right angle with the shank and its end is then ground squarely 
across, it forms an instrument with a double cutting edge that may 
be effectively operated for either a push or draw cut when due consider- 
ation is given to the angle at which either of the effective cutting edges 
is applied to the tooth root. Instruments to be used exclusively for 
draw cutting or scraping should be given a slight bevel in the direction 
toward which the cutting is done, while those which are to be operated 
with a pushing force are most effective when the ends are ground square, 
although some operators prefer a slightly bevelled cutting edge even in 
scalers of the push cutting type. Whatever may be the choice as to 
angle of edge, it is essential that the edge be kept sharp if effective work 
is to be accomplished with it. Besides proper curvature of shank and 
character of working edge, it is of paramount importance that the 
working ends of root scalers be so delicately fashioned that they may be 
readily inserted to the ultimate depth of pyorrheal pockets without 
unduly disturbing the pocket or wounding the gum tissue, and it is 
equally important that they be so tempered that they will not break or 
permanently bend in use. The necks and shanks should be given a blue 
spring temper and the cutting ends a light brown or straw color. It is 
not necessary, nor is it desirable that the points should be left full hard, 
as in certain enamel cutting instruments. 

Finally, the matter of handles is by no means unimportant, for the 



TREATMENT 



487 



reason that in the most difficult and delicate part of the operation of 
root scaling the operator must be guided by his tactile sense alone in 
locating the deposits and determining when the root surface is smooth 
and free from concretions. For this reason the handle of the instrument 
must be of such size, weight, and form as will interpose the least possible 
barrier to the accurate transmission of the tactile impression. The 



Fig. 552 





60 



61 



character of instrument handle is largely a question of individual 
experience and experiment, and each operator, especially those who to 
a greater or less extent specialize in the treatment of pyorrhea cases, 
should discover by careful study and experimentation for himself the 
type of scaler handle best adapted to his individual use, and through 
which he can best receive an intelligible understanding of the conditions 



Fig. 553 



Fig. 554 





9 10 

Abbott's scalers. 



7 11 

Darby-Perry scalers. 



he has to meet in the removal of root deposits by instrumentation, and, 
above all, his equipment of instruments should be ample to enable him 
to meet all operative requirements. 

A selection of twenty-five scalers which will enable the beginner to 
meet ordinary conditions is shown in Figs. 552 to 558. The numbering 
is that of the manufacturers' catalogue, which has been retained for 



488 



PYORRHEA ALVEOLARIS 



identification. This equipment should be added to as the need for 
more specialized forms arises and after experience has developed 
facility in the use of those in the collection illustrated. 



Fig. 555 



Fig. 556 





Harlan's scalers. 



4 5 6 7 

Tompkin's pyorrhea scalers. 



For the preliminary breaking up of calcareous deposits the writer 
has devised a form of scaler with a dentate cutting edge which serves 
a useful purpose in dislodging the thin scale-like tartar deposits upon 
tooth roots (Fig. 558). The dentate edges of these instruments will 
break up such a deposit often when a smooth-edged instrument will 
fail to penetrate it. The dentate scaler should be followed by the use 
of a smooth-edged instrument to remove any adhering small particles 
of concretion and to give to the root a smooth surface. 



Fig. 551 





Adair's scalers. 



2 6 

Kirk's dentate scalers. 



Besides the difficulty of access and the obscurity of location which 
ordinarily prevents the use of direct vision as an aid in determining the 
position of calcareous deposits on the roots of teeth, the operation of 



TREATMENT 489 

scaling for the removal of subgingival tartar is complicated by the slight 
hemorrhage incidental to the operation, and not infrequently by the 
pain which attends it. Various means may be employed to control 
both of these conditions. 

Asepsis. — It is as important here as in any other surgical operation 
that the principle of asepsis should be applied and practically utilized, 
and while it is not possible under the conditions presented to secure 
a sterile field of operation, it is quite possible to greatly dimmish the 
bacterial content of the mouth and to largely eliminate the sources of 
infection from the field of operation. 

Preparatory Details. — In undertaking the scaling operation in a 
typical pyorrhea case it is assumed that it is for a patient who gives 
average attention to the details of the daily dental toilet, and that the 
teeth, as a whole, are therefore reasonably free from fermenting deposits 
or putrefactive debris. If the teeth are, however, not in a reasonably 
clean state, and show evidences of carelessness or neglect as to ordinary 
oral cleanliness, the necessary instructions as to thorough cleansing 
with brush and dentrifices should be given and the case dismissed until 
a later sitting, when these instructions shall have been carried out. 
When the case again presents, the field of operation should be pro- 
tected from saliva by a properly adjusted napkin, then dried with 
spongoid, cotton, or bibulous paper, followed by a continuous blast 
of warm air at about 110° or 115° F., and painted with official 
tincture of iodin U. S. P., which contains 7 per cent, iodin. The gums 
and teeth should be well stained with the iodin, which cannot be satis- 
factorily done in the presence of moisture, and as the whole denture 
cannot, under the circumstances, be dried at once, the drying and 
coating with iodin must be done over a convenient area at one time and 
the operation repeated over a new area until all of the involved teeth 
have been so treated. The action of the iodin is threefold — it is an 
efficient germicide and antiseptic, it is slightly astringent, and in the 
strength prescribed it is a stimulant to the vascular supply and cell 
activity of the disordered tissues. After the iodin application, all 
visible deposits of salivary tartar should be removed and the teeth 
polished with fine pumice. Attention should next be directed to the 
subgingival deposits and concretions upon the roots. 

Removal of the Deposits. — The operation of scaling and cleansing the 
teeth has thus far been considered from the standpoint of the denture as 
a whole. It is now of vital importance to the success of the operation that 
the operator concentrate his attention exclusively upon the individual 
tooth under treatment, and that he devote his time and his manipula- 



490 PYORRHEA ALVEOLARIS 

tion to that particular tooth until he is convinced that its root or roots 
are free from deposits of whatever character before proceeding to treat 
the next. The operation must be thorough and the removal of deposits 
complete; the ideal should be to remove the last particle of tartar, that 
which is in contact with the marginal attachment of the pericementum; 
all those particles which precede the last one are of relatively minor 
importance, for if the last one be allowed to remain, the whole operation 
results in failure. Patient, persistent thoroughness, a cultivated touch, 
and educated skill are all requisites for success in this phase of the 
treatment. 

Control of Hemorrhage. — During the course of the operation often 
the flow of blood will so obscure the field that at times it may become 
an annoying interference with further progress. A certain amount of 
hemorrhage in the early stages of the work may be deemed beneficial, 
as it relieves the engorgement of the gingival tissues usually present in 
these cases, for which reason the flow of blood may for a time be properly 
encouraged by a stream of warm water slightly above body temperature. 
Ordinarily the flow of blood will decrease when the tissues have thus 
relieved themselves of their abnormal engorgement, but if it persists 
to an annoying extent it may be reduced or even completely arrested 
by a stream of water as hot as can be borne by the tissues thrown 
against them from a syringe, or concentrated hydrogen dioxid (10 
per cent.) touched to the pockets or bleeding surface is an efficient 
hemostatic. The hemorrhage may be positively controlled by an 
application of trichloracetic acid (10 per cent.) applied to the bleeding 
surface. Stronger concentrations should not be used, as they have a 
destructive action upon the soft tissues. A most useful adjunct in the 
treatment of pyorrhea cases for the control of oozing of blood or serum 
into the pocket, for cleansing the pocket from debris and rendering it 
patulous, so that from time to time a direct view of the root and interior 
of the pocket may be obtained in favorable situations, is the forcible 
injection of heated air under high pressure, as first suggested and 
advocated by Dr. H. C. Register, of Philadelphia. 1 

Control of Pain. — The margin of the pericementum when irritated and 
inflamed by contact with subgingival tartar is often exquisitely sensi- 
tive, a condition which in nervous patients prevents that passive sub- 
mission to the treatment necessary to the performance of so delicate 
and difficult an operation. Under such circumstances, to relieve pain 
and secure passivity of the patient, it is advisable and proper to induce 

1 The Treatment of Dental Lesions by Compressed Warmed and Dried Air, 
H. C. Register, Dental Cosmos, vol. xxvii, p. 594. 



TREATMENT 491 

local anesthesia of the gingival and pericemental margins. This can 
usually be accomplished by means of the topical application of a con- 
centrated cocain hydrochlorid solution. A twist of cotton is saturated 
with the solution and packed with a suitable instrument under the gum 
and allowed to remain in situ for a few minutes. The region should be 
made dry pieviously to the application, and it will then usually be 
found that the sensitiveness has disappeared. If the topical application 
should fail to relieve the hypersensitiveness, then resort may be had to 
a subgingival injection of a 1 per cent, cocain or 2 per cent, novocain 
local anesthetic solution in the same manner and under the same pre- 
cautions as are necessary in the induction of local anesthesia for tooth 
extraction. (See Chapter XVIII.) 

Chemical Aids to the Scaling Operation. — The resistive texture of sub- 
gingival tartar deposits and their firm adherence to the root surface has 
led to the use of acid solvents as an aid to disintegrating the refractory 
deposits by chemical means. Dilute sulfuric acid (acidum sulphur icum 
dilutum U. S. P., 10 per cent. H,S0 4 ), or the official aromatic sulfuric 
acid (acidum sulphuricum aromaticum) , containing 20 per cent, of 
absolute H 2 S0 4 , has been highly recommended, especially by Professor 
James Truman, not only as a means for chemically loosening tartar 
deposits upon the roots of teeth, but also for its value in disintegrating 
the necrotic alveolar margins and stimulating the subjacent vital tissues 
to healthy reparative action. 

Strong lactic acid has been extensively used for the same purpose 
and for the same general reasons; it has the advantage of higher solvent 
power for tricalcic phosphate, which it dissolves without leaving a 
residue; sulfuric acid, on the contrary, converts the tricalcic phosphate 
into calcium sulfate, setting free the phosphoric acid, and unless the 
sulfuric acid be sufficiently dilute, its action tends to be superficial and 
self-limiting, owing to the formation of a protective layer of calcium 
sulfate upon the surface of the tartar nodule. The self-limiting action 
of strong sulfuric action upon dentin is well shown in Calahan's 
method of root canal treatment 

Trichloracetic acid also aids in the disintegration of deposits of tartar 
on roots of teeth, but both trichloracetic acid and lactic acid are 
coagulators of mucin, and their action upon the mucinous binding 
element of the tartar deposit tends to inhibit their otherwise useful 
solvent action upon the earthy mineral constituent of the tartar. 

In a paper on "A Tartar Solvent Especially Useful in Pyorrhea 
Work," 1 Dr. Joseph Head reported an investigation which he had made 

1 Transactions National Dental Association, 1899, p. 131. 



492 PYORRHEA ALV SOLARIS 

of the action of acid ammonium fluorid as a solvent of tartar deposits, 
and announced as the result of his studies that a solution of the salt in 
question possessed the remarkable property of disintegrating tartar 
deposits, while it was without action upon tooth structure. The prepa- 
ration of the inventor is sold in the depots under the proprietary name 
of "Tartasol." Reports as to its efficiency on the whole support the 
claims made for it, although a few cases of undue escharotic action 
from its use have been reported, and its application is generally reported 
to be painful. While any acid compound of hydrofluoric acid should 
be used with caution in contact with living tissues because of the well- 
known destructive action of hydrofluoric acid, the preparation in 
question, if its free acid is sufficiently neutralized to control its eschar- 
otic effect, should be a valuable adjunct to pyorrheal treatment not 
only because of its professed action as a tartar solvent, but more par- 
ticularly because of the well-known germicidal action of the fluorin 
compounds with the alkali bases. 

After-treatment. — When the teeth and exposed root surfaces have 
been freed of all deposits of extraneous matter of whatever nature by 
appropriate operative means, the retentive and surrounding tissues 
usually require further treatment to bring about a return to normal 
conditions. The principles governing the treatment relate to restoration 
of disordered circulation in the involved tissues, reestablishment of 
their normal tone, and the prevention of reinfection, to accomplish 
which, local astringent, stimulant, and antiseptic applications should 
be judiciously made; massage of the gum tissue may be employed, and 
the daily use of an appropriate lotion by the patient, together with 
the most scrupulous attention to the details of the dental toilet, should 
be insisted upon. 

As a local application which is stimulant, germicidal, and astringent, 
to immediately follow the conclusion of operative treatment of the 
teeth, the iodoglycerol of Talbot is of much value. It consists of a 
solution in which the germicidal properties of iodin are reinforced by 
the astringent and antiseptic properties of zinc iodid. The formula is 
as follows: 

Zinc iodid 15 parts 

Water 10 " 

Iodin . . 25 " 

Glycerin 50 " 

An analogous combination, more complicated in its mode of prepa- 
ration but essentially the same in therapeutic efficiency, although less 
liable to exert an escharotic effect for the reason that it is not so con- 



TREATMENT 493 

centrated, is W. J. Younger's preparation, which is made as follows: 
Mix equal parts of No. 1, a saturated aqueous solution of zinc sulfate, 
and No. 2, a saturated solution of iodin in a solution of potassium iodid, 
1 ounce; watei, 4 ounces. The reaction of the potassium iodid with 
the zinc sulfate in Younger's formula results in the formation of zinc 
iodid and potassium sulfate, which latter salt in time crystallizes out, 
leaving a supernatant solution of zinc iodid and iodin, which is the 
effective therapeutic combination of the preparation. Either of these 
solutions applied by means of an appropriately shaped orange-wood 
point, or upon asbestos fiber wrapped around an aluminum wire appli- 
cator, will render the surface of the tissue impregnable to bacterial 
invasion and destroy infection to a considerable depth in the tissue; at 
the same time the astringent properties of the zinc iodid exert a stim- 
ulant and supporting effect, restoring tone to the capillary system. The 
topical application of these solutions should not be repeated oftener 
than twice or three times per week, as opportunity should be given for 
healthy tissue to form, which too frequently repeated treatment by such 
concentrated solutions of iodin and zinc iodid would tend to prevent. 
G. V. Black has recommended the treatment of pyorrheal pockets and 
necrotic areas with the following: 

Oil of cassia 1 part 

Phenol, cryst 2 " 

Oil of wintergreen 3 " 

Campho-phenique has also been recommended for the same purpose. 

James Truman strongly advocates the packing of pockets with 
quinin sulfate. Any mild antiseptic, stimulant, and astringent appli- 
cation which is sufficiently lasting when applied to the tissues in 
question will produce favorable results. The iodin and zinc iodid 
preparations of Talbot and Younger respectively have, in the 
experience of the writer, given more satisfactory results in the first 
phase of the local after-treatment of pyorrhea than any other medica- 
ment tried. 

As a lotion for daily use by the patient nothing has yielded such 
definitely satisfactory results in the writer's experience as the following: 

Py. — Zinci chloridi 5j 

Aquae menthse piperitae f5viij 

Sig. — Apply to the gums on a cotton swab, t. i. d. 1 

1 Zinc chlorid appears to have been first recommended for this use by the late 
Professor Charles J. Essig, who also suggested the use of dilute sulfuric acid as a 
means for softening and disintegrating refractory tartar deposits upon tooth roots. 
See an important paper on Some of the Causes of Loss of the Teeth in the Adult, 
by Charles J. Essig, M.D., D.D.S., Dental Cosmos, 1880, vol, xxii, p. 130. 



494 PYORRHEA ALVEOLARIS 

The patient should be directed to avoid swallowing any of the lotion, 
and the application should be made after the teeth have been cleansed 
by brushing following the regular meals. 

The prognosis is favorable in cases where the essential predisposing 
cause of the pyorrhea is tartar of salivary origin or tartar, mucoid and 
salivary, girdling the tooth below the anatomical neck acting trau- 
matically. 

PYORRHEA HAVING A CONSTITUTIONAL PREDISPOSITION 

Loss of the teeth by a necrotic inflammatory process involving their 
retentive structures and wholly without the intervention of tartar 
deposits as a factor in the process is a common phenomenon well 
established by observation and experience. It is equally well estab- 
lished that loss of the teeth in these cases is generally associated with 
other objective phenomena indicating aberrations of various kinds 
from the normal standards of bodily health. The nutritional fault 
may be so slight as to escape casual notice, or may even be unrecognized 
by the patient; or, on the other hand, the destructive action going 
on in the retentive structures of the teeth may be definitely concurrent 
with a clearly defined and well-recognized bodily disease. The asso- 
ciation of tabes dorsalis, leukemia, syphilis, arthritism, diabetes mellitus, 
various forms of nephritis, tuberculosis, etc., and the prolonged mal- 
nutrition often following typhoid, pneumonia, malaria, and other 
types of acute infection are matters of observation and record by both 
physicians and dentists. So also disorders which have their origin in 
defects of the nutritional mechanism; the diseases of metabolism, so 
called, are more or less constantly associated with pyorrheal disease of 
the dental retentive tissues, especially when the individuals so affected 
are well advanced in adult life, and not infrequently at an earlier period 
if the nutritional fault is pronounced and chronic. The disease may 
attack a single tooth or several at one time, or in comparatively 
rare instances the teeth of the entire denture may.be simultaneously 
involved. 

Tartar deposits may or may not be present, and if present, may have 
no direct causal relation to the destructive inflammatory action. On 
the other hand, certain calcareous deposits found upon tooth roots of 
this class of pyorrheal cases are distinctly a result rather than the 
cause of the local inflammation. 

The type of pyorrhea associated with constitutional or general 
nutritional disorders differs essentially in its clinical manifestations by 



PYORRHEA HAVING A CONSTITUTIONAL PREDISPOSITION 495 

reason of the depth of the invasion of the retentive structures by the 
pathogenic bacteria which are the exciters of the inflammatory process 
under consideration. The localized gingivitis and subsequent pyorrheal 
condition caused by the impingement of salivary tartar upon the 
marginal gum tissue is superficial and ulcerative in type, while that 
due to deeper invasion of the retentive tissues by pathogenic organisms 
made possible by the lowered internal or vital resistance of the tissues 
from malnutrition or constitutional disease is characterized by deep 
pus-pocket formation or by the tendency to periodically form abscesses. 

Numerous investigators have endeavored to isolate the specific 
organism which it has been assumed might be the exciter of this destruc- 
tive process, and while the search thus far has yielded no definite results 
in so far as the discovery of a single specific organism as the cause of 
pyorrheal infection is concerned, the evidence thus far attained points 
strongly to the conclusion that the organism mainly concerned in the 
causation of the type of pyorrhea here under consideration is the pneu- 
mococcus, 1 which acts as the initial exciter of the inflammatory process, 
and that the reaction produced by that organism is supplemented by a 
secondary invasion of the infected region by the Streptococcus pyogenes 
and Staphylococcus pyogenes aureus and its congeners. In short, it 
appears to be a mixed infection in which the pneumococcus plays 
the role of leader in an attack which is followed by organisms of 
relatively less virulence. 

The predilection of the peridental membrane to infection by the 
pneumococcus has been definitely noted and reported upon by numer- 
ous observers; indeed, the periosteum of the entire mandible has been, 
in several cases, found to be the seat of destructive inflammatory 
action set up by pneumoccocal infection alone, or associated with 
Staphylococcus pyogenes aureus, and in cases of general constitutional 
disease, where from the nutritional interference the natural defensive 
forces of the tissues are below their normal health standard, invasion 
of the pericementum by the pneumococcus, which is an almost constant 
inhabitant of the oral cavity, is prone to occur. 2 

The path of the infection is in all probability along the network of 
cells described by Black as the "glands of the peridental membrane" 
(see page 472), and who found in the microscopic examination of a 

1 It is recognized that reports of bacteriological studies of pyorrheal exudates by 
no means uniformly record the presence of the pneumococcus. It is regrettable 
that in many instances the methods employed and especially the composition of the 
culture media is not stated. By the methods stated at p. 511 the practical con- 
stancy of the pneumococcus in pyorrheal exudates has been determined. 

2 See under General Considerations, p. 469, a discussion of the principles involved 
in the relation of normal health status to defence against bacterial invasion. 



496 PYORRHEA ALVEOLARIS 

tooth extracted from a patient suffering from ''phagedenic pericemen- 
titis" (the type of pyorrheal inflammation here under consideration) 
" that some of the lymphatics near the gingival border of the membrane 
were in a state of suppuration." This condition followed the lymph 
chains in the direction of the apex of the root to a distance which the 
author says surprised him, "considering the very slight signs of the 
disease before the removal of the tooth, and seemed especially confined 
to these cells." He says, further: "This case hints quite strongly that 
these lymphatics are the seat of this very peculiar affection." 1 While 
further scientific study of this phase of the matter is needed to thoroughly 
classify the question of the part played by these structures described 
by Black as glands of the peridental membrane, as the pathways of 
bacterial invasion in pyorrheal disease, clinical observation tends 
to amply confirm the observations made on the case quoted that these 
so-called glands are the pathway through which the infection takes 
place. 

Exception may be fairly taken to the designation of these structures 
as glands. From studies made by the writer, the assumption of their 
glandular character does not appear to be warranted. The cellular 
elements of which they are composed, their morphology, and their 
relation to the embryological development of the tooth germ and its 
related tissues point to the conclusion that the so-called lymphatics 
of the peridental membrane are remnants of the epithelial sheath of 
Hertwig, 2 which in the adult membrane constitute " rests" of epithelial 
debris having the characteristics of a degenerative tissue. Examples 
of embryonal resting cells are found in many other locations in the 
body, which under irritation are prone to take on morbid activity, and 
also by reason of their degenerate character and low resistance are 
under favorable conditions peculiarly liable to infection. 

The appearance of the structures in question is clearly shown in 
Fig. 559. 

The epithelial origin of these so-called "lymphatics" is by no means 
a recent belief as to their character and significance. 

Magitot 3 first advanced the hypothesis that the epithelial layer 
forming the inner wall of cysts of the peridental membrane was derived 
from the wall of the dental follicle. Malassez 4 confirmed and further 

1 Periosteum and Peridental Membrane, p. 93. 

2 Ueber das Zahnsystem der Amphibien, Archiv. fur mikroskopische Anatomie, 
Supplementheft, 1874. 

3 Memoire sur les Kystes des Machoires, Arch, gener. de Medecine, 1872, tome 
ii, pp. 339-414 et 681-699; Memoire, etc., 1873, tome i, pp. 154-174 et 437-486. 

4 Sur l'existence d'amas epitheliaux autour de la racine des dents chez 1'homme 
adulte a l'etat normal, Arch, de physiol., 1885, tome i, p. 129. 



PYORRHEA HAVING A CONSTITUTIONAL PREDISPOSITION 497 

extended the view of Magitot, while von Brunn, 1 by a thorough and 
elaborate microscopic study of the embryological development of the 
dental follicle, furnished the anatomical and histological data upon which 
a rational understanding of the process by which the epithelial structures 

Fig. 559 




Reproduced from Fibers of the Peridental Membrane. G. V. Black, Dental Cosmos, vol. xli, 
p. 111. Glands of peridental membrane shown with yV-inch lens, in which the characters of the 
cellular elements appear. D, dentin; Cm, cementum; Cb, cementoblasts; Gl and Gl 2 , loops of 
glands in focus showing the cells; Cp, hyaline capsule enclosing gland, which also appears 
about Gl 2 . 



found in the peridental membrane are derived from the embryonal 
epithelial cells that originate the enamel organ and are further extended 
upon the tooth root, through the peridental membrane, to and inclusive 
of the root apex in the adult. Concerning this extension of epithelial 

1 Ueber die Ausdehnung des Schmelzorgans und seine Bedeutung fur die Zahn- 
bildung, Arch. f. mikr. Anatomie, Band xxix, 1887. 
32 



498 PYORRHEA ALVEOLARIS 

cells, von Brunn's conclusion as stated by Dr. Witzel 1 is as follows: 
"The enamel organ extends not only as far as enamel is subsequently 
formed, but proliferates beyond the limiting border of the enamel and 
gradually covers the entire tooth germ up to the apex of the tooth." 
This proliferation of the enamel organ had already been described by 
O. Hertwig, 2 and v. Brunn adopted Hertwig's term epithelial sheath 
for this sheath-like epithelial process. 

Infection of the epithelial nests distributed as a network throughout 
the structure of the pericemental membrane leads to inflammatory 
reaction not only of the membrane itself, but of the bony alveolar 
walls and the bone of the alveolar border, and the gingival tissue as 
well, resulting in a series of pathological and morphological changes in 
these structures characteristic of the destructive disorder, and ending 
in the loss by exfoliation of the involved teeth. 

With loss of the teeth the disease is arrested, for the reason that the 
tissue in which the infection originates, viz., the peridental membrane, 
no longer exists as a factor in the process. For the same reason extrac- 
tion and replantation of pyorrhetic teeth will effect a cure of the dis- 
orders in connection with teeth so treated, the peridental membrane 
being functionally destroyed by the operation, union of the replanted 
tooth to its alveolus being brought about by ankylosis. Similarly, 
destruction of the peridental membrane and irritation of the socket 
walls by the excessive use of scalers results favorably to the cure of the 
disease by eliminating to a greater or less degree the peridental mem- 
brane as a factor and reestablishing union between the socket and 
tooth root by bony encapsulation or ankylosis. 

The exact nature of the destructive action of the disease upon the 
bony tissue of the alveolar sockets has not as yet been definitely made 
out. 

A. Hopewell-Smith 3 is of the opinion, based upon careful micro- 
scopic study of the diseased tissues, that " The disease of the bone is not 
in its earlier stages a rarefying osteitis. . . It is essentially depend- 
ent upon an osseous lesion, an atrophy of the bone which in the thinnest 
parts causes the cervical margins of the teeth to become denuded 
through the halisteresis (osteomalacia) and osteoclastic absorption. 
The presence of serumal calculus is not sufficient in itself to induce the 
condition, and may not be associated with it at all as a predisposing or 

1 Ueber Zahnwurzelcysten deren Entstehung, Ursache und Behandlung, Leipzig, 
1896, p. 10. 

2 Ueber das Zahnsystem der Amphibien, Arch. f. mikr. Anatomie, Supplement- 
heft, 1874. 

3 Dental Cosmos, vol. liii, p. 409. 



PYORRHEA HAVING A CONSTITUTIONAL PREDISPOSITION 499 

exciting cause." The osteoclastic destruction of the alveolar bone is 
not infrequently extended to the pericementum, producing clearly 
marked evidence of root absorption about the apical extremities of 
teeth lost through pyorrheal disease. 



Fig. 560 



'\ ': . ."7 



i. 



\ 



c 



I 

14'Tl 



,;' \ 



m 



. 




r] 


: 




"" *H:-V "- '-., 






i : 




\ 




• / 






r 


\ A. 

r 




.• """* — ~ **•■«* — - 


•.iiJJSsM. 


-*. 




^ 


j? 



; :-/./ 



Vortical section through canine and right maxilla of man, aged twenty-eight years, showing latest 
stages of extremely acute conditions associated with pyorrhea alveolaris. Lateral section (X35). 
.4, apex of root formed by hyperplasia cementum; B, hyperplastic peridental membrane; C, 
indifferent tissue enormously increased in amount and more vascular than usual; D, soft 
medullary tissue exhibiting signs of hyperplasia; E, large osteoparotic space; F, sequestrum of 
bone undergoing peripheral absorption; G, osteoclasts producing lacunas absorption of the bone 
of the socket; H, bone of socket partially destroyed and converted into osteoid tissue; /, line 
of junction of decalcified and normal bone. Preparation and photomicrograph by A. Hopewell- 
Smith. 



The alterations of histological structure in the tissues involved in 
pyorrhea alveolaris are shown in Fig. 560, reproduced from a photo- 
micrograph of a section through the tooth root and its retentive tissues 
by A. Hopewell-Smith, 



500 PYORRHEA ALVEOLARIS 

Destructive inflammatory lesions of the gingival and alveolar tissues, 
more or less simulating pyorrhea alveolaris, occasionally occur, due to 
specific infections; for example, syphilitic invasion of the gingival 
margins, or infections following the use of mercury as an antisyphilitic 
remedy. 1 The clinical history and the atypical appearance of these 
lesions will, however, furnish the data necessary to a clear differential 
diagnosis. A form of destructive gingival and alveolar inflammation, 
which may be mistaken for an acute expression of ordinary pyorrhea 
alveolaris of a phagedenic type is that produced by an invasion of 
the Bacillus fusiformis and spirochete of Vincent's angina. The his- 
tory of the case will show that the inflammatory attack is essentially 
acute in character and differs from ordinary pyorrhea alveolaris in 
that the disorder promptly yields to local applications of iodin following 
curettement and hot water irrigations of the necrotic alveolar margins. 
In a doubtful case, bacteriological examination of the exudate will 
clear up the diagnosis. 

Finally, scorbutus, 2 both in the adult and as occurring in improperly 
fed children, produces a marginal gum and alveolar lesion which in 
certain stages closely simulates pyorrheal disease of the alveolar border. 
The history of the attack and an examination of the food habit, together 
with the existence of the other lesions typical of scorbutus, e. g., hemor- 
rhagic infarcts of the skin simulating purpura hemorrhagica, soreness of 
the articulating ends of the long bones, and, in children, motor paralysis 
enuresis, etc., w T ill determine the nature of the constitutional disorder 
responsible for the mouth lesion and indicate the therapeutic proce- 
dures necessary for the correction of the disorder. 

The deep invasion of the peridental membrane by pathogenic organ- 
isms in cases where the defensive agencies of the body are below normal 
frequently leads to the production of abscesses which are extremely 
painful, causing much distress to the patient during the period of their 
development, which ordinarily run a course of from a week to ten days, 
although in certain situations they may run a shorter course. The pus 
exudate may burrow its way between the cementum and the alveolar 
wall to the gum margin, in which case the so-called pus pocket, or pyor- 
rheal pocket, is formed as the fistulous outlet; or when the focus of 
infection is located near the root apex in the case of a tooth so situated 
that the line of tissue resistance between the focus of infection and the 
gum margin is greater than that Ipetween the focus of infection and the 

1 See A. Loup, Considerations on the Role of Mercury in Mercurial Stomatitis 
Dental Cosmos, 1900, xlii, 1300. 

2 Kirk, E. C, Two Cases of Infantile Scorbutus, Dental Cosmos, xxxvii, 1895, 
489, and discussion, pp. 503 to 51 1 , 



PYORRHEA HAVING A CONSTITUTIONAL PREDISPOSITION 501 

overlying gum surface, then the fistulous outlet takes place upon the 
free gum surface, and the case becomes one of so-called abscess upon a 
tooth with a vital pulp, or, as designated by Dr. D. D. Smith, a peri- 
cemental abscess. 1 



Fig. 561 



562 



Fig. 563 





Fig. 564 



Specimens showing pericemental abscess at A, B, and C respectively. 

Fig. 564 will indicate diagrammatically the relation of the locus of 
infection to the resistance of the surrounding tissue in determining the 
part of the fistulous outlet. A represents an inflammatory focus near the 
root apex with fistulous outlet upon the free gum surface. B, a similar 
inflammatory focus near the anatomical neck of the tooth with fistulous 
outlet at the gingival margin D. The etiology 
and pathology of both lesions is the same; 
they differ clinically by reason of the location 
of the point of fistulous discharge due to loca- 
tion of the initial lesion. In the case of the 
lesion A, the fistulous outlet would have oc- 
curred at the gingival margin C had the part 
of resistance toward C been less than toward 
the gum surface over A. 

Much confusion as to the pathological sig- 
nificance of these abscesses has arisen by 
reason of the fact that they occur upon teeth with vital pulps. Their 
relation to pyorrhea alveola ris is, however, perfectly clear, and the 
clinical phenomena which they manifest are due solely to the depth 
of the bacterial invasion which is the exciter of the suppurative pro- 
cess, this deep invasion leading ultimately to a fistulous outlet upon 




D. D. Smith, Pericemental Abscess, Dental Cosmos, 1897, xxxix, 569. 



502 PYORRHEA ALVEOLARIS 

the gum surface instead of at the gum margin, with pocket formation, 
as ordinarily occurs where the invasion is of less depth. 

Bacteriological examination of the pus taken from a limited number 
of cases of pericemental abscess showed pneumococci and staphylococci 
as the principal organisms, and these may be regarded as the exciters 
of the inflammatory process. The pericemental abscess is typical of 
that form of pyorrhea alveolaris associated with a constitutional pre- 
disposition or systemic fault due either to bodily disease or to nutri- 
tional or metabolic error, which has reduced the defensive agencies 
of the body below normal and thus rendered deep invasion of the reten- 
tive tissues by pathogenic bacteria possible. 1 

Pyorrhea alveolaris may constitute a cause of malnutrition, or it may 
be a result of malnutrition. Infection of the gingival and alveolar 
tissues by pyogenic and other pathogenic organisms, besides leading to 
the inflammatory destruction of the involved tissues, coincidently leads 
to the production of toxic end products of bacterial activity, which, 
taken into the circulatory system, either directly from the seat of 
infection or via the digestive tract, set up a chronic toxemia of greater 
or less intensity which in time may lead to pronounced disturbances of 
health, both local and general, and not infrequently to metastatic 
infections, causing grave disease manifestations in various tissues and 
organs of the body. For which reason, thorough and systematic treat- 
ment, directed toward the correction of the local pyorrheal disorder, 
should be persistently carried on until the disease is under control. 2 
On the other hand, certain forms of pyorrhea alveolaris are distinctly 
local expressions of faulty nutrition, and particularly of that type which 
in its collective or general expression is designated the arthritic diathesis 
or gouty diathesis, characterized by a subnormal oxidizing power and 
in which the pathological manifestations are of the class known as 
diseases of suboxidation. Cases of this class present a form of general 
malnutrition in which the metabolic mechanism appears to be 
incapable of completely converting proteid materal into its normal 
physiological end products, with the result that the whole of the excess 

1 For a fuller discussion of pericemental abscess consult the following : 
Magitot, E. Memoires sur les tumeurs perioste dentaire et sur l'osteo-periostite 

alveolo-dentaire, Paris, 1873. 

Essig, Chas. J. Some Causes of Loss of the Teeth in the Adult, Dental Cosmos, 
1880, xxii, 130. 

Darby, Edwin T. Proc. Odontological Society of Pennsylvania, February, 1880, 
in Dental Cosmos, 1880, xxii, 248. 

Kirk, Edward C. Abscess upon Teeth with Living Pulps, Dental Cosmos, 1898, 
xl, 621; Pericemental Abscess, Dental Cosmos, 1900, xlii, 1149. 

2 See Oral Sepsis as a Cause of Septic Gastritis, Toxic Neuritis, and Other Septic 
Conditions, by Dr. Wm. Hunter, Physician to St. George's Hospital, London. 
London and New York, Cassell & Co., 1901. 



PYORRHEA HAVING A CONSTITUTIONAL PREDISPOSITION 503 

nitrogen, instead of leaving the body as urea, a soluble bland and 
non-irritating waste product, is partially retained and deposited in 
various of the tissues as members of the purin group and allied 
relatively insoluble compounds, which in certain positions become 
sources of chemical and mechanical irritation leading to cell death, 
so-called necrobiosis of tissue elements, and by thus establishing areas 
or loci of diminished resistance become the forerunners of local in- 
fections. 

Chemical and microscopic examination of the tartar deposits upon 
tooth roots from patients of the class under consideration has amply 
demonstrated the presence of urates as the nucleus around which the 
deposit of calcic phosphate has taken place, thus confirming the arthritic 
origin of the lesion, which in its pathological character is strictly the 
analogue of the tophus of true gout. 

Pyorrheal lesions of the arthritic type are relatively deep-seated, and 
less inclined to be marginal in their expression. The case presents a 
history of soreness and lameness and increasing looseness of the teeth, 
with but little or no visible pus formation. Atrophic changes in the 
alveolar walls become progressively manifest, and from time to time 
local tumefactions and swellings, indicating pus formation, occur over 
the roots of the more noticeably affected teeth. These acute localized 
inflammatory tumefactions may or may not develop into abscess for- 
mations. 

In the earlier stages of these localized lesions the inflammation 
frequently subsides without discharge of the pus exudate, but later 
the swelling recurs, and in due course a minute abscess discharges its 
exudate upon the free gum surface, after which resolution or healing 
of the inflamed area takes place, to be repeated later, with more exten- 
sive involvement, until the tooth is finally lost. 

Teeth extracted after having passed through the cycle of inflammatory 
phenomena here described will frequently show upon some portion of 
the root near the apex tartar formations even though there may have 
been no break of continuity in the attachment of the peridental mem- 
brane and gum tissue at the anatomical neck of the tooth. The tartar 
deposits in such cases are, therefore, unquestionably not salivary in 
origin, but are derived from the liquor sanguinis, and are properly 
designated as serumal or sanguinary tartar. Their mode of formation 
is explainable upon the same basis as the calcic formations that are 
found in old abscess cavities in other tissues of the body, notably in the 
lung, lymphatic glands, etc. Chemical and microscopic examination 
of these concretions in connection with the clinical historv of the cases 



504 PYORRHEA ALVEOLARI S 

of pyorrhea alveolaris, in which they occur, throws considerable light 
upon the method of their formation. It is a well-established physio- 
logical fact that a tissue, such as muscle or ligamentous tissue, doing 
active work rapidly undergoes metabolic changes while in action, and 
that in consequence of the increased oxidation involved, the reaction 
of the tissue tends toward acidity or relatively lessened alkalinity. 
Under these circumstances an area of lessened alkalinity in the tissues 
of an arthritic individual whose blood stream is carrying dissolved urates 
to the saturation point becomes a nidus in which precipitation of 
urates takes place. Irregular position of a tooth, or habit of the indi- 
vidual, will subject a given tooth to more than its physiological share 
of the burden of work in mastication, and thus make it the point of 
selection for a uratic deposit by developing, through overwork of a 
particular tooth, an area of decreased alkalinity in its investing peri- 
dental membrane and thus make it the point of selection or deter- 
mination of the pyorrheal attack, just as the articulation of the distal 
phalanx of the great toe, from the relative prominence of its part in 
walking, becomes the point of selection for a localized acute inflamma- 
tory manifestation in classic gout. Deposition of urates in the selected 
area is followed by localized cell irritation and limited cell death, and 
the disturbed area constitutes a locus minoris resistentice in which in- 
fection takes place and the suppurative phenomena already described 
follow. Where resolution takes place in one of these areas without 
formation of fistula, caseation by dehydration of the retained abscess 
debris takes place, and final infiltration of the mass by calcic salts 
occurs by reason of the fact that the mass is now alkaline in reaction, 
due to the pus formation, and the final result is a tartar nodule hav- 
ing a nucleus of uratic salts around which has been deposited a mass of 
tricalcic phosphate bound together by the organic residue of the pus 
exudate. 

The close relationship of arthritic malnutrition to pyorrheal involve- 
ment of the retentive tissues of the teeth is now clearly recognized, and 
the constitutional predisposition induced by arthritism to bacterial 
invasion is found to be dependent upon a diminished tissue resistance 
with lowering of the opsonic index, which in many cases is amenable 
to autogenous vaccine therapy, under which treatment the opsonic 
index has been raised to normal with cure of the local lesion. 1 

While arthritic individuals, especially those whose dietary is over- 

1 See The Association of Disease of the Mouth, with Rheumatoid Arthritis and 
other Forms ot Rheumatism, Hunterian Lecture, by Kenneth W. Goodby, Lancet, 
March 11, 1911, p. 639; also Arthritism, by E. C. Kirk, Dental Cosmos, July, 1909. 



TREAT MEXT OF ALVEOLAR PYORRHEAL INFECTIONS 505 

balanced on the proteid side, represent a type of malnutrition which 
renders them especially liable to infection of the alveolar tissues by 
pyogenic organisms, it may be stated, as a broad principle, that any 
nutritional disorder which results in depression of the natural defensive 
agencies of the body, when sufficiently prolonged, is liable to become a 
predisposing cause of pyorrhea alveolaris. Rhein 1 has directed atten- 
tion to this relationship of constitutional predisposition arising out of 
various systemic diseases, and has suggested a basis of classification of 
pyorrheal lesions as related to their etiology in that connection. 2 

Nutritional disturbance from neuroses, hereditary predisposition, and 
developmental errors have been shown by Talbot 3 to act as etiological 
factors leading to pyorrheal infection of the alveolar structures. 



TREATMENT OF ALVEOLAR PYORRHEAL INFECTIONS HAVING 
A SYSTEMIC PREDISPOSITION 

It is a fundamental axiom of therapeutics that the cure of a disease 
must involve the removal of its cause. As the cure of suppurative 
inflammatory lesions of the retentive structures of the teeth due to the 
impingement of tartar as a traumatic predisposing cause necessarily 
involves the thorough removal of tartar deposits as a prerequisite to 
successful local treatment of the inflammatory lesion, so also in pyor- 
rhea alveolaris, due to constitutional malnutrition, treatment of the 
local lesion is without permanent curative effect until the underlying 
systemic fault has been effectually corrected. The mere routine local 
treatment by scaling and the application of antiseptic, stimulant, 
escharotic, or astringent drugs is of but temporary benefit; indeed, 
misdirected or ill-judged routine local treatment may do positive harm 
in cases of this class. A large proportion of pyorrheal cases having 
a constitutional predisposition, cases of the most intractable class 
have practically no tartar deposits whatever upon the tooth roots, and 
yet the empiric to whose mind tartar and pyorrhea are interchangeable 
terms, subjects such teeth to a vigorous application of the scaler to 
scrape the roots smooth even when no tartar is to be found upon them. 
Such ill-advised treatment wounds the gingival tissues, increases the 

1 Oral Expressions of Malnutrition, Dental Cosmos, 1896, xxxviii, 486; Pyorrhea 
Alveolaris, Dental Review, March, 1899. 

2 An Etiological Classification of Pvorrhea Alveolaris, Dental Cosmos, 1894, 
xxxvi, 779. 

3 See Interstitial Gingivitis or Pvorrhea Alveolaris, by Eugene S. Talbot, M.D., 
D.D.S., 1899. 



506 



PYORRHEA ALVEOLARIS 



Fig. 565 



opportunity for further infection, and lessens the already weakened 
resistive powers of the local tissue area involved. Careful exploration 
with a suitable delicately fashioned, exploring instrument should be 
made to first determine the presence or absence of tartar deposits before 
any attempt at scaling in these cases is made. Where tartar is not the 
obvious cause of the pyorrheal lesion, careful study of the character of 
the local gingival conditions should be made, the quantity and character 
of the pus flow should be noted, and the extent of atrophy or rarefaction 
of the alveolar borders determined. For the latter purpose the radio- 
graph is a most valuable aid in diagnosis (Fig. 565). Where it is possible 
to do so, cultures from the exudate should be made and the nature of 
the infecting organisms determined. The history of the patient, the 
existence of systemic disease, or nutritional fault should be ascertained, 

and where doubt exists as to the nutri- 
tional or metabolic status of the patient, a 
careful urinary and salivary analysis should 
be made. 

An almost unlimited number of antisep- 
tic drugs have been suggested and tried for 
disinfecting the pus pockets and infected 
tissues in pyorrheal cases. Many are ob- 
jectionable for the reason that they exert 
a destructive action upon the tissue cells 
as well as upon the invading pathogenic 
organisms. The ideal antiseptic is one 
that will exert a destructive effect upon 
the bacteria without injury to the tissue 
and at the same time have diffusive or 
penetrating power sufficient to enable it to reach the organisms deeply 
embedded in the infected tissues. Among the more recent remedies 
which have been favorably reported upon is bismuth subnitrate made 
into a paste with vaselin, the formula being Bismuth subnitrate, 33 
per cent.; vaselin, 67 per cent. 

This preparation injected by means of a warmed syringe into pockets 
and sinuses has been found to arrest pus formation markedly, and 
cures of alveolar pyorrhea are reported from its use. 1 

Another preparation which practical test has shown to have a marked 
value for the same use is silver iodid of 5 per cent, strength in an emul- 
sion made with Irish moss (Chondrus).. The preparation was first 




Radiograph of the alveolar border 
of a patient suffering from pyorrhea 
alveolaris, in which the rarefaction 
of the bony tissue due to decalcifica- 
tion is clearly shown. Note also the 
resorption of the apex of the *ight 
canine root. 



x See Bismuth Paste as a Dental Therapeutic Agent, Rudolf Beck, D.D.S., Dental 
Review, 1909, xxiv, 1079. 



TREATMENT OF ALVEOLAR PYORRHEAL INFECTIONS oO] 



Fig. 566 



11! 



employed in the treatment of urethritis in accordance with the following 

formula : 

1$. — Argenti nitratis pulv., 

Potassii iodidi aagr.lv 

Aquae dest 5yj 

Mucilago chondri q. s. fgiij 

Dissolve the potassium iodid in all of the water and gradually add 
the silver nitrate in powder, shaking after each addition until all of the 
silver nitrate is dissolved, then add the mucilage and 
shake thoroughly. This method of compounding the 
emulsion is necessary in order to obtain the precipi- 
tate of silver iodid in an extremely finely divided 
state and keep it in suspension: The emulsion should be 
kept away from strong light. 

For the application of medicaments to the infected 
pockets and sinuses in pyorrhea cases the device known 
as the "pyorrhea pen" is a most convenient and 
efficient means (Fig. 566). The instrument consists of 
a suitable handle in which is fixed a split metal holder, 
which by means of a rectangular sliding collar is made 
to grasp a pen-like double point of pyralin, the two 
leaves of which form a capillary space between them. 
The flexible points may be used either in single or 
double form, and because of the convex shape given 
to them by the clamping device, when dipped in the 
remedy a sufficient quantity is retained in the spoon- 
shaped depression and between the two points for 
application, without a surplus to overflow and spread 
upon surrounding healthy tissues. 
. A quantity of points is furnished with each instru- 
ment so that a new point may be used with each case. 
They may be altered in position with reference to 
the grasp of the holder, for greater convenience in 
reaching difficult cases, or altered in form by reshaping 
with scissors for special situations as needed. 

In all cases where the progress of the disease has 
resulted in appreciable loosening of the teeth, the local 
treatment should be supplemented by some means 
for affording surgical rest to the teeth until reestab- 
lishment of healthful condition of the tissues has 
rendered them firmer in their sockets and capable 
of withstanding the ordinary stress of mastication. rhea pen 



508 PYORRHEA ALVEOLARIS 

A variety of means for splinting the loosened teeth have been 
suggested, and many ingenious mechanical appliances have been 
devised for that purpose. It is beyond the scope of this chapter to take 
up in detail the construction of these appliances, and for information 
upon that class of work the reader is referred to standard works on 
mechanical dentistry. A simple and effective device for securing surgical 
rest of pyorrhetic teeth during the stage of healing and recuperation of 
their alveolar structures consists in weaving a floss silk ligature about 
the disordered teeth so as to include one or more sound teeth at each 
end of the series of loose teeth, making several figure-of-eight turns 
of the ligature throughout the whole series, and then painting the liga- 
ture with a thick solution of celluloid in acetone, which rapidly hardens 
and makes an effective supporting splint that will not become loosened 
or deteriorate in many cases for two or three months. It should be 
understood that in placing the above described splint, the surfaces of 
the teeth, the ligature, etc., should be kept dry until thorough hardening 
of the celluloid solution has taken place. The drying of the solution 
may be hastened by applications of a warm air blast. 

It is obviously without the sphere of the operative dental practi- 
tioner to undertake the treatment of the underlying constitutional 
aberrations that predispose to alveolar infections; it is, however, dis- 
tinctly within his province to be able to recognize intelligently these 
mouth lesions as indications of general bodily disease or nutritional 
errors, and to be able not only to direct the patient to a physician for 
treatment, but also to aid in the diagnosis of the systemic fault by reason 
of his knowledge of the relationship of the various objective phenomena 
or symptoms presented by these alveolar lesions to the several systemic 
states with which they are connected. In order that the dentist may 
secure the training necessary to fit himself to diagnose correctly the 
nature of these alveolar lesions, it is essential that he cooperate with the 
physician and keep in touch with the medical treatment of the case, 
while the local dental treatment is being concunently carried out. The 
knowledge gained from the medical study and treatment of the systemic 
condition will in due course enable the dental practitioner to determine 
from a study of the mouth lesion, the general and often the special nature 
of the constitutional fault which is the underlying predisposing factor 
in the case, and when armed with such knowledge, enable him also to 
point out often constitutional disorders in their earlier stages and before 
the patient has otherwise become aware of their existence. 

The question of the curability of the type of pyorrheal disorder here 
under consideration is so frequently the subject of discussion, and its 



VACCINE THERAPY OF ORAL INFECTIONS 509 

solution depends so obviously upon the scope of meaning that may be 
attached to the term cure, that it is important to briefly and definitely 
consider the matter here. 

Where the alveolar infection is consequent upon a lowered vital resist- 
ance of the infected tissues due to constitutional disease or general 
malnutrition, local treatment, while it may arrest the progress of the 
disorder temporarily or keep it under control for a variable period of 
time, cannot alone effect a cure in the sense that the tendency to a 
recurrence of the disorder is permanently eradicated. The permanent 
cure of this type of pyorrhea alveolaris necessitates the eradication of 
its predisposing constitutional cause just as the permanent cure of 
pyorrhea due to infection consequent upon tartar deposits necessitates 
the removal of the tartar as a predisposing cause. In either case, where 
the predisposing cause is constantly operative, local treatment alone, 
which is necessarily intermittent, will ultimately fail to effect a perma- 
nent c^ure. When both the predisposing cause, be it local or systemic, 
and the local infection can be eradicated, the disorder is unquestionably 
curable. 

When the lowered resistance of the patient is mainly due to absorp- 
tion of toxins, and when the resulting malnutrition is not due to specific 
constitutional disease, prompt and permanent restoration of the infected 
gingival tissues to health may be brought about by the judicious appli- 
cation of vaccine therapy. So satisfactory has this method of treat- 
ment proved in a fair proportion of otherwise intractable cases, that 
the following description of the method is here appended: 

VACCINE THERAPY OF ORAL INFECTIONS 1 

In common with other local pathological conditions, brought about 
through the agency of bacteria, affecting various parts of the exterior 
and interior of the animal economy, certain infections of the oral 
cavity and its adnexa coming within the domain of the dental prac- 
titioner are amenable to the action of bacterial vaccines — not 
only those due primarily to the invasion of the tissues by pathogenic 
bacteria, but also conditions in which such organisms are present as 
secondary invaders of a pathological process originally due to some 
other deleterious agent. In the treatment of these conditions the 
mistake is, however, frequently made of depending entirely on the 

1 This addition to the chapter on Pyorrhea Alveolaris is contributed by Nathaniel 
Gildersleeve, M.D., Assistant in the Bacteriological Laboratory, University of 
Pennsylvania. 



510 PYORRHEA ALVEOLARIS 

vaccines and instituting no other local or general therapeutic measures 
in combating the diseased conditions; if this procedure is adhered to 
the results of bacterical therapy will, in a large percentage of cases, be 
disappointing. 

Manifestly, bacterial vaccines will not exert a curative action on 
factors other than bacterial, entering into a causative relationship to 
diseased conditions; inoculations will frequently eliminate the bacterial 
element and, in so far as the infective nature of the condition is con- 
cerned, bring about a marked improvement or cure; leaving, however, 
the predisposing factors unchanged and still capable of exerting an 
irritative action on the tissues, paving the way for a fresh infection 
to be grafted into the process. These points are of as much importance 
in connection with oral infections as with those occurring in other parts 
of the economy. 

In considering the subject of vaccine treatment of oral infections 
there are certain principles which the operator should have firmly 
fixed in his mind, and from which he must not depart if satisfactory 
results are to be expected. The most important of these are as follows: 

I. A thorough familiarity with all pathogenic organisms capable of 
causing infections in the oral cavity and surrounding tissues; with the 
different species concerned in the various types of infection and with all 
pathological conditions in which bacteria may be present as secondary 
invaders. 

II. A knowledge of the types of infection, and the toxic substances 
produced by the various organisms, together with the various types of 
immunity active against each species. Such knowledge will prevent 
the operator employing a vaccine in attempting to combat the ravages 
of an organism against which these substances will not immunize. 

III. Always become satisfied, by microscopic examination and 
cultural methods of the exact nature and identity of the organism or 
organisms concerned in the individual infection under treatment. 

IV. Use vaccines known as autogenous, i. e., vaccines prepared from 
the pathogenic organisms isolated from each case; and if more than one 
species is present, to which may be ascribed an etiological relationship 
to the condition, employ a mixed vaccine or, separately vaccines pre- 
pared from each organism. He should not depend on stock vaccines 
or treat any case empirically. 

V. Exercise judgment and discretion as regards the dosage and 
interspacing of inoculations, watching the patient's condition carefully, 
and always be in a position to control the injections by determining 
and interpreting the opsonic index, 



VACCINE THERAPY OF ORAL INFECTIONS 511 

VI. Employ in conjunction with the vaccines other local and gen- 
eral therapeutic measures capable of exerting a curative influence 
on the process, removing, as completely as possible, all sources of 
irritation. 

VII. Always take into consideration the patient's general condition. 
There are frequently underlying systemic factors lowering the resistance 
of the tissues, thus paving the way for local infections. 

For methods of isolating and identifying the various organisms, the 
reader is referred to one or another of the works on the subject of 
bacteriology, as an attempt to enter into a detailed description of such 
methods would involve the writing of a text-book on the subject. A 
few points of importance regarding plating media for the isolation of 
bacteria from the oral cavity had perhaps best be mentioned. There 
are organisms, playing an important part in infections, inhabiting the 
oral cavity which many fail to isolate, for the reason that suitable media 
are not employed. Notable among these is the pneumococcus. Milk 
agar, milk serum agar, blood serum agar, or blood agar should be 
employed routinely when dealing with bacteria of the oral cavity, and 
the cultures incubated at 37° C, under both ordinary and anaerobic 
conditions. 

These media are readily prepared by keeping on hand, in tubes con- 
taining about 5 c.c, sterile milk, milk serum, and blood serum, and 
adding one or another of them to tubes of a 2 per cent, nutrient agar, 
after it has been liquified and cooled to 42° C, in the proportion of 
1 part to 3 parts of the nutrient agar. 

Preparation of Vaccines. — In the preparation of vaccines all apparatus, 
containers, and solutions employed must be sterile, and great care 
taken to prevent extraneous organisms from gaining access to the 
vaccines. 

Several slant cultures are made on the surface of tubes of suitable 
media, from a freshly isolated pure culture of the organism, and incu- 
bated at 37° C. for from eighteen to twenty-four hours; the organisms 
are then washed from the surface of the media with 0.85 per cent, 
sodium chloiid solution and transferred to a sterile bottle or test- 
tube containing sterile glass pearls or a small amount of clean sterile 
sand. The container is now tightly stoppered or sealed and shaken, 
either by hand or in a mechanical shaker, for the purpose of breaking 
up clumps and producing a homogeneous distribution of the bacteria 
throughout the suspension. A small amount of the suspension is then 
removed and the number of bacteria per cubic centimeter estimated 
by counting with a Thoma-Zeiss hemocytometer, using a counting cell 



512 PYORRHEA ALVEOLARIS 

of yV mm - depth; or by mixing, in a capillary pipette, equal parts of the 
bacterial suspension, 2 per cent, sodium citrate solution and blood 
obtained by puncturing the finger or lobe of the ear, this mixture 
is spread thinly on slides, fixed and stained by an appropriate 
method. 

The number of bacteria and erythrocytes in 100 microscopic fields 
are counted with the aid of a yV oil immersion lens and the number 
of bacteria per cubic centimeter estimated by a mathematical 
deduction assuming that 1 c.c. of blood contains 5,000,000,000 
erythrocytes. 1 

The suspension of bacteria is next placed in a tube, the end sealed, 
and the tube immersed in a water bath and heated, at approximately 
the lowest thermal death point of the organism, for a sufficient period to 
kill the bacteria. The suspension is then diluted to the desired strength, 2 
with 0.85 per cent, sodium chlorid solution, 0.2 per cent, of phenol or 
tricresol added, subcultures made for the purpose of determining its 
sterility, and the vaccine, which we now call the bacterial suspension, 
pipetted into 1 c.c. ampoules, which are then sealed, making a closed 
container, which cannot become contaminated. The suspension is 
diluted to the extent that 1 c.c. of vaccine will contain the number of 
organisms constituting the proper maximum dose; when less than the 
maximum dose is desired, it can readily be measured by employing a 
graduated hypodermic syringe. 

The Opsonins and Opsonic Index. — Metchnikoff demonstrated the 
phenomenon of phagocytosis, ascribing to the leukocytes, notably the 
polymorphonuclear, and certain other tissue cells, the function of 

1 Equation for estimating number of bacteria per cubic centimeter of suspension : 
E : B : : E' : X 

E = number of erythrocytes per microscopic field. 

B = number of bacteria per microscopic field. 

E'= number of erythrocytes per cubic centimeter of blood. 

X = number of bacteria per cubic centimeter of suspension. 

Example: In 100 microscopic fields of slide there were counted 800 bacteria 
and 400 erythrocytes. The number of bacteria per field = 8 and of erythrocytes 4; 
1 c.c. of blood contains 5,000,000,000 erythrocytes. The number of bacteria per 
cubic centimeter of suspension = 10,000,000,000. 

4:8:: 5,000,000,000 : X = 10,000,000,000. 

2 Formula for dilution of vaccine: 
S 

1 = Q. 

V 

S = number of killed bacteria in suspension. 

V = number of killed bacteria desired in vaccine. 

Q = number of volumes of salt solution required to produce desired dilution. 

Example: Suspension contains 10,000,000,000 bacteria per cubic centimeter; 
a vaccine containing 250,000,000 is desired. 

10,000,000,000 -h 250,000,000 =40—1 =39 volumes of salt solution to be 
added to 1 volume of suspension. 



VACCINE THERAPY OF ORAL INFECTIONS 513 

engulfing and digesting bacteria. He advanced the phagocytic theory 
of immunity. 

This attracted the attention of scientists for a number of years, 
but was practically lost sight of by the majority following the pro- 
mulgation of Ehrlich's theory; a few, however, still occupied them- 
selves with researches on phagocytosis, and, among other facts, it was 
demonstrated that when the leukocytes were freed from serum they lost 
the function of phagocyting the majority of species of bacteria, but when 
serum was added this function again became manifest. This demon- 
strated thef act that serum was necessary for the phagocytic phenomenon, 
and it was claimed by some that serum stimulated the leukocytes to 
exert this function. It remained for Wright to demonstrate that when 
leukocytes washed in sodium-citrate-chlorid solution, for the purpose 
of freeing them from serum, were brought in association with bacteria 
that had previously been treated with serum, the phagocytic phenome- 
non again became manifest, thus proving conclusively that the serum 
element necessary for phagocytosis acted not, as was supposed, on the 
leukocytes, but upon the bacteria, preparing them for the engulfing 
function of the phagocytes. To these substances Wright gave the name 
of opsonins. 

The opsinins may be defined as vital tissue elements, circulating in 
the body fluids, having the property of acting upon bacteria, so as to 
prepare them for phagocytosis. These elements exist normally in the 
tissues (normal opsonins), and act as one of the normal defences against 
the invasion of the tissues by bacteria; they are decreased by many 
factors exerting a deleterious influence on the normal metabolic processes 
of the economy, rendering the individual more susceptible to infection; 
they are likewise decreased in certain infections, and can be markedly 
increased by active immunization (immune opsonins) by means of the 
bacterial vaccines. 

The fact must be borne in mind, that while immunity against certain 
species of bacteria is apparently wholly opsonic, in the case of other 
species it is not only opsonic, but there are other elements, as agglu- 
tinins, bacterioly sins," and antitoxins, exerting an antibacterial function; 
further, that there is no evidence of opsonic immunity in connection 
with protection against certain other species of bacteria. The opsonic 
index is the opsonizing power of a given serum as compared with 
that of one or more normal sera taken as a unit. This index guides 
the operator as regards the amount of vaccine to be employed as the 
initial dose, and the intrespacing and increasing of subsequent doses. 

The greater the depression of the opsonins the smaller should be the 
33 



514 



PYORRHEA ALVEOLARIS 



initial dose of vaccine, and the more carefully should the following 
doses be increased and interspaced. 

To illustrate this, let us consider the phenomena presenting in a 
case of infection not only as it appears for treatment, but following the 
injection of vaccine. An index determination will show a greater or 
lesser depression of the opsonins toward the organism concerned in the 
infection; following the injection of a vaccine there appears after from 
six to twenty-four or forty-eight hours a further depression of the opson- 
ins, which condition is termed the negative phase; later, if the dose 
has not been too large, or the resistance of the individual too low, we 
will find a rise in the opsonins to or above that exhibited before inocula- 
tion, this is termed the positive phase; a second inoculation should not 
be made until the establishment of this phase; when a second dose of 
vaccine will give rise to a less marked negative phase followed by a 
more pronounced positive phase; these phases present in order following 
subsequent inoculations until the index rises to or above normal, i. e., 
when the opsonizing power of the patient's serum equals or exceeds 
that of the normal controls. The rapidity with which this condition 
is established depends on: 

The Type of Infection; Degree of Depression of Opsonins; General Con- 
dition of the Patient and the Care Exercised as Regards the Dosage and 
Interspacing of the Vaccine. 

Fig. 567 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 








l.-> -fe 






1 3 Ct- ° £ 


i - a .§ npr / 




Qj i.<* o o ,- r 


h i o e _^-U_^ / 


- h % , .p PT ^ 


° i° tl / 


z - J s !o S / 


eo ft o i° r * a * / 


£ - 8 § 'o & ."' '^- ? 


° 7 oT_ S S 2l " d 


•7 . ^s -Q- ^ y* 


R oV -F- ^ ^ J 


•6 H2 Tex io^ ^ 7 


r, ^ +' x y «- 


.O or- - ^ oT ^ ^ 


4 \ *' " 


•* N ^^ 


o tr' 





Chart showing effect of inoculations in a case of streptococcous infection of the nasal sinus. Note 
negative and positive phases following the injection of vaccine, beginning with 10,000,000 and in- 
creasing to 100,000,000. Circles indicate the index. 



Technique of Determining the Opsonic Index. — Apparatus required: 
An opsonizer: This consists of a copper box, with two openings in 
the top, for a thermoregulator and a thermometer. Through this box 
are soldered horizontallv brass tubes, f inch inside diameter; the size 



VACCINE THERAPY OF ORAL INFECTIONS 515 

of opsonizer and number of tubes can be varied to suit the require- 
ments of the operator. A high-speed centrifuge, fitted with small tubes 
for washing the blood and separating leukocytes. A small mechanical 
shaker will be found a very convenient part of the outfit. Wright's 
capillary pipettes, made of y^- to i inch glass tubing; pieces of the tubing 
about 6 inches long are heated in the middle by means of a Bunsen or 
blast flame and drawn out to a diameter of about -3V inch; the distal 
end is fitted with a small rubber bulb. Serum pipettes, for collecting 
and separating the serum; these are about 2i inches long, of thin glass 
tubing, one end drawn out straight, the other drawn out and bent at 
an angle of 45 degrees. Other apparatus required include a microscope; 
microscope slides and cover-glasses; a blood stylet; sterile bottles, 
tubes, and glass pearls; sterile volumetric and capacity pipettes. 

Reagents required include 0.85 per cent, sodium chlorid solution, 
a 1 per cent, sodium citrate solution in 0.85 per cent, sodium chlorid 
and suitable bacterial and blood stains. 

Further, we require a bacterial emulsion, washed leukocytes, serum 
from patient; normal sera, preferably from three or four normal indi- 
viduals; if the serum of but one healthy person is used it should be com- 
pared every few days with several other normal sera, and if more than 
a very slight variation is noted, the several sera employed. 

The bacterial emulsion is prepared by cultivating the organism on 
suitable media for eighteen to twenty-four hours; washing it off with 
sterile salt solution; emulsifying in a sterile bottle or tube containing 
glass pearls; some bacteria are readily emulsified when shaken by hand, 
while others must be placed in a shaking apparatus, the latter procedure 
being preferable in all cases. After emulsifying and diluting the sus- 
pension, it is centrifugalized for one or two minutes, to remove any 
clumps that may remain. The density is then determined by opsonizing 
with normal serum to obtain its so-called phagocyting index, or by com- 
paring it with a barium sulfate standard (McFarland's nephelometer), 
and then diluted to the proper strength; it is stated that it should be of 
such density that when opsonized with normal serum each leukocyte 
will ingest from five to eight of the ordinary bacteria. Some prefer a 
suspension of somewhat greater strength; the counts are more difficult, 
but the results are, it is claimed, more uniform. 

Washed leukocytes are obtained by filling two of the small centrifuge 
tubes three-quarters full of citrate solution; then wrapping the finger 
with a rubber band, so as to cause congestion at the end, make a punc- 
ture with a stylet at the root of nail or side of finger, and allow the blood 
to fill the citrate tubes. It is then mixed by inverting tubes several 



516 PYORRHEA ALVEOLARIS 

times, and centrif ugalized ; when the corpuscles are well packed and the 
supernatant fluid is clear, remove the solution carefully, so as not to 
disturb the corpuscles, fill with 0.85 per cent, sodium chlorid solution, 
and again centrifugalize. It is best to repeat the latter process twice 
to make sure that all of citrate and serum has been washed out; remove 
the salt solution carefully, to avoid disturbing the layer of leukocytes 
which will have collected on the surface of the sediment; the last drops 
are best removed by inclining the tube and inserting a capillary 
pipette at the upper part of the meniscus. The upper layer of sediment, 
containing the leukocytes, is removed with a clean capillary pipette and 
placed in a small sterile tube. This is then thoroughly mixed by drawing 
in and out of the pipette, being careful to avoid admixing air bubbles. 
This so-called leukocyte cream will contain with the leukocytes some 
erythrocytes. These appear to be advantageous, as better results are 
obtained when they are present than when leukocytes alone, the true 
leukocyte cream, are employed. 

Serum is obtained by puncturing the finger, and allowing blood to 
flow into the curved end of the blood pipette until a sufficient quantity 
is obtained; the tube is then grasped lengthwise between the thumb and 
forefinger and the point of the straight end warmed and sealed in the 
flame. As the end of the tube cools the blood in the curved end is drawn 
into the body. The tube can be placed in the opsonizer or incubator for 
fifteen to twenty minutes, when the serum will usually be separated; 
if not, the tubes may be centrif ugalized for a few moments. When the 
serum is required, the tubes may be notched on one side with a file and 
readily snapped off with the fingers or by touching with a hot glass point. 

Method of Determining Index. — The opsonizer should be placed on a 
table to the right or left of the operator; sera, leukocyte cream, bacterial 
suspension, and all necessary apparatus in front; all within reach, as one 
must work quickly and accurately, and each tube be timed as it is 
placed in the opsonizer. A mark is made with a paraffin pencil on the 
capillary pipette, three-quarters of an inch from the end; the rubber 
bulb is connected and the mixture made by drawing substances into 
the tube in the following order: 1 volume of leukocytes, a bubble of air, 
1 volume of bacterial suspension, a second bubble of air, 1 volume of 
serum — some add to this a second volume of leukocytes, varying the 
technique in this respect, with excellent results. The writer has found 
this of value especially when the stronger bacterial suspension is em- 
ployed. The contents of the pipette is then emptied into the con- 
cavity of a concave slide and thoroughly mixed by drawing in and out of 
the pipette several times, care being taken to get rid of all air bubbles, 



VACCINE THERAPY OF ORAL INFECTIONS 517 

as this interferes to some extent with phagocytosis; the mixture is 
drawn into the pipette, the end sealed quickly, and placed in the opson- 
izes where it is left for exactly fifteen minutes; some incubate for twenty 
minutes — this makes little or no difference. The important point to 
bear in mind is that all tubes, the preparations to be tested and controls, 
must be opsonized for the same length of time, as a matter of a few 
seconds frequently makes more difference in the results than one 
would imagine. The point of pipette is then broken off and the contents 
expressed on one end of two or three clean glass slides and spread evenly 
over the surface by placing the end of another slide in contact with the 
drop and drawing it over the first; this, if properly done, yields a thin 
even smear. Some employ a specially made spreader, but this will be 
found unnecessary, as one can make perfect smears with a little practice 
by using the end of an ordinary slide. The preparation is allowed to 
dry in the air, and stained with Wright's or some other blood-stain; if 
one should employ the ordinary aqueous staining solutions, the prepara- 
tion must be first fixed by treating for a minute with methyl alcohol. 
The technique for staining is the same as for ordinary blood films with 
which anyone who will undertake the work is familiar. 

The number of bacteria ingested by two hundred leukocytes are 
counted in each preparation, i. e., those made with patient's and normal 
sera used as a unit. Some investigators pool the normal sera and make 
but one unit preparation; this is not a good practice, as the pooled 
sera preparations frequently vary quite markedly from those made 
with each serum separately. After counts are made, divide the number 
of bacteria ingested per leukocyte (phagocyting index) in the prepara- 
tions made with patient's serum, by the number ingested per leukocyte 
in those made with the normal sera, which gives the opsonic index. 

Many will meet difficulties in making these preparations. One great 
source of trouble to beginners is controlling the pipette so as to obtain 
exact amounts of each ingredient in making the mixture. Accuracy 
can only be attained by practice. The pipette can be handled best by 
grasping between the middle and third finger, and the bulb between 
the thumb and index finger. 

Method of Making Inoculation. — After having decided on the dosage 
of vaccine to be employed, a 1 to 2 c.c. hypodermic syringe, having a 
glass barrel and fitted with a needle of comparatively small lumen, 
is carefully sterilized and filled with the vaccine. The skin over the 
site chosen for inoculation is cleansed with a 2 per cent, phenol solution, 
followed by sterile water and absolute alcohol, and the needle intro- 
duced into the subcutaneous tissue. The site of inoculation is preferably 



518 PYORRHEA ALVEOLARIS 

just below the angle of the scapula, outer side of upper arm, the buttocks, 
thigh, or outer side of the leg. 

The dose of vaccine to be given varies according to the organism 
employed; the degree of depression of index; the type of infection; age 
and physical condition of the patient. In many instances the dose 
employed has been too large and some of the poor results reported are 
undoubtedly due to this fact; it is always best to start with a small 
dose and increase. No absolute rules can be laid down regarding the 
size of the dose; in general it can be said that smaller doses should be 
employed when the index is very low than when moderately depressed; 
in general, if employed at all, than in local infections; in acute than in 
chronic conditions; in children and individuals markedly depressed and 
in poor condition than in adults and the more robust. The doses of the 
various vaccines that will commonly be employed in treating infections 
of the oral cavity range about as follows: 

Micrococcus aureus and albus, 50,000,000, 100,000,000 to 
600,000,000. 

Streptococcus pyogenes, 10,000,000, 25,000,000 to 100,000,000. 

Pneumococcus, 10,000,000, 25,000,000 to 100,000,000. 

Micrococcus catarrhalis, 25,000,000, to 100,000,000. 

Influenza bacillus, 25,000,000 to 100,000,000. 



CHAPTER XVI 

DISCOLORED TEETH AXD THEIR TREATMENT 

By EDWARD C. KIRK, D.D.S, Sc.D. 

Discoloration of a tooth is a result of death of its pulp. 
While death of the pulp does not always or necessarily involve dis- 
coloration of the tooth structures, yet when the condition does exist the 
general cause is as stated. Reference is here made to a progressive 
interstitial staining of the entire dentin structure, and is exclusive 
of certain metallic stains, also of localized stains resulting from the 
imbibition of pigmentary matters occasionally observed where small 
areas of dentin have become denuded of enamel covering, or where 
the latter has been so imperfectly formed as to afford an insufficient 
barrier to the ingress of pigmentary matters from the food or oral 
secretions. 

Three classes of conditions are presented for consideration and treat- 
ment: First, cases where discoloration has resulted from death of the 
pulp due to causes other than its exposure; second, discoloration from 
pulp death consequent upon exposure; and third, special discolorations 
due to adventitious causes superadded to the conditions affecting the 
cases included in the foregoing second division. 

Any of the numerous traumatic causes which bring about death of 
the pulp, e. g., blows, sudden contact with hard substances, biting 
threads, violent thermal shocks, the injudicious application of continuous 
force in regulating, or the application of arsenous oxid to the dentin, 
where no exposure or only minute exposure of the pulp exists, may 
produce hyperemia and congestion of the pulp, or strangulation 
of its circulatory system, the formation of emboli, thrombus, hemor- 
rhagic infarct, etc., leading to a breaking down of the corpuscular 
elements of the blood, the escape of hemoglobin from the stroma 
of the red corpuscles, its solution in the blood plasma, and resulting 
infiltration of the tubular structure of the dentin by the hemoglobin 
solution, giving the tooth a distinctly pinkish hue when examined by 
direct or transillumination. 

Suffusion of the dentin structure by discharged hemoglobin may be 
readily produced by the topical application to the exposed pulp of 
medicaments having a hemolytic property, for example, trinitro- 
glycerin, glonoin, as an ingredient of a cocain solution intended for 
the production of local anesthesia, will not infrequently produce hemo- 

(519) 



520 DISCOLORED TEETH AND THEIR TREATMENT 

lysis with suffusion of the dentin when the mixture is locally applied 
to a bleeding pulp. Even distilled water exerts a hemolytic effect, 
rupturing the stroma of erythrocytes by endosmosis; therefore, all 
solutions intended for topical application to a bleeding pulp should be 
at least isotonic with the plasma or preferably of greater density in order 
to avoid staining the dentin with diffused hemoglobin. 

Teeth so affected rapidly change in color through various gradations 
in tint from the original pinkish hue, which becomes yellow; this, grow- 
ing darker, passes into brown, and after the lapse of considerable time 
the tooth may become a permanent slaty gray or black. 

The violence of the hyperemia preceding the death and disintegration 
of the pulp in a considerable degree determines the rapidity of the 
process of subsequent tooth discoloration. When congestion of the 
pulp has been relatively slight and the necrotic process has proceeded 
slowly, the sudden infiltration of the dentin with hemoglobin does not 
occur, consequently the initial change in color following complete death 
of the pulp may be so slight as to escape detection except upon most 
searching examination with special means of illumination, and even 
then may be manifested only by a slight diminution in the normal 
translucency of the tooth as compared with adjoining teeth. Such teeth, 
however, if permitted to remain untreated, eventually grow darker, 
and while they may not acquire a degree of discoloration equal to those 
which have suffered sudden and violent death of the pulp, still they 
become so unsightly as to demand treatment for the restoration of 
their normal color. 

The Rationale of the Process of Discoloration. — In teeth discolored as 
a consequence of the death of the pulp without its exposure — viz., 
those of the first class — it is evident that the sources of pigmentation 
are internal to the tooth and are to be sought for solely in the products 
of decomposition of the elements of the pulp tissue and of its vascular 
supply. 

The proteid elements of the pulp tissue are complex combinations 
of carbon, oxygen, hydrogen, nitrogen, sulfur, and phosphorus, which 
in their gradual breaking down by the process of putrefactive decom- 
position are split up finally into carbon dioxid, water, ammonia, and 
hydrogen sulfid, with possibly the formation of traces of phosphatic 
salts. The group of substances entering into the composition of the 
histological elements of pulp tissue contains no constituents which in 
the progressive changes resulting from putrefactive decomposition 
should form compounds likely to cause permanent discoloration of 
the tooth structures. 

When, however, the vascular supply is considered as a factor, the 
explanation of the cause of discoloration in the cases in question becomes 
reasonably clear. The red blood corpuscles contain as their charac- 
teristic component hemoglobin or oxyhemoglobin according as the blood 



THE RATIONALE OF THE PROCESS OF DISCOLORATION 521 

is venous or arterial, and this substance is its essential coloring ingre- 
dient. When undergoing gradual decomposition, hemoglobin passes 
through a variety of alterations in its chemical constitution, accompanied 
by a corresponding series of color changes. 

A familiar illustration of these color changes is furnished by the 
cycle of color alterations witnessed in a bruise. Immediately following 
an injury to the flesh, of the character alluded to, an extravasation of 
blood in the bruised territory occurs, causing undue reddening of the 
skin; this is soon followed by an increasing darkening of the tissue, 
until there results what is popularly termed a " black-and-blue spot." 
Further decomposition of the coloring matter of the extravasated blood 
induces a variety of color changes ranging through the scale of yellows 
and browns, until the pigmentary matter is finally removed by absorp- 
tion through the capillary bloodvessel system of the part. 

In passing through the cycle of color changes due to its progressive 
decomposition, hemoglobin undergoes several alterations in composi- 
tion, among which are formed a number of definite compounds, each 
having marked chromogenic features. Of these decomposition products, 
methemoglobin (brownish red), hemin (bluish black), hematin (dark 
brown or bluish black), and hematoidin (orange), are the most im- 
portant and best known. While the gradual decomposition of the color- 
ing matter of the blood here noted may and doubtless does account 
for certain phases of tooth discoloration, other factors which exert a pro- 
foundly modifying influence upon the process are yet to be considered. 

The putrefactive decomposition of the proteid elements of the pulp 
results, as before stated, in the production of hydrogen sulfid in con- 
siderable quantity. The albumins contain from 0.8 to 2.2 per cent, of 
sulfur (Hammersten), which in the splitting up of the compound during 
putrefaction yields a large amount of hydrogen sulfid. In pulp decom- 
position this hydrogen sulfid is generated in contact with the hemo- 
globin, and necessarily exerts a marked modifying action upon the de- 
composition process of that substance. Miller says: "If a current of 
hydrogen sulfid is conducted through fresh blood or a solution of 
oxyhemoglobin in the presence of air or oxygen, sulfomethemoglobin 
is formed, which is greenish red in concentrated solutions and green in 
dilute solutions. If we lay a freshly extracted tooth in a mixture of 
meat and saliva so that a part of the enamel surface remains free, and 
moisten the surface with blood, it will take on a dirty green color if kept 
at blood temperature in an absolutely moist condition for from twenty- 
four to forty-eight hours. It is quite possible that the dirty green 
deposits which form in putrid conditions of the mouth, in stomatitis 
mercurialis, scorbutica, gangrenosa, etc., or even in inflammatory con- 
ditions of less importance, as well as in cases of absolute neglect of the 
care of the mouth, may owe their green color to the presence of 
sulfomethemoglobin. ,, 



522 DISCOLORED TEETH AND THEIR TREATMENT 

As in pulp decomposition hydrogen sulfid is being formed in the 
presence of hemoglobin, this fact warrants the belief that a combina- 
tion takes place resulting in the formation of this same compound, 
which Miller regards as productive of certain stains upon the external 
surface of the teeth. 

The slaty gray or bluish pigmentation always noticeable upon the 
visceral walls and frequently beneath the skin of animal bodies under- 
going putrefactive decomposition is a familiar example of the action of 
hydrogen sulfid or its ammonia combinations upon decomposing hemo- 
globin in hemorrhagic extravasations, and is a process and form of pig- 
mentation exactly analogous to that which is here described as taking 
place in the dentinal structure from putrefactive decomposition of the 
pulp. "When red corpuscles are just beginning to disintegrate, the 
coloring matter formed is hemoglobin; but the yellow and brown 
granular masses found in cells and lying free in tissues are, as a rule, 
derivatives of hemoglobin, not hemoglobin itself. These derivatives 
are divided into two groups according as they contain iron or not, the 
former being called hemosiderin, the latter hematoidin." 1 "When acted 
upon by ammonium sulfid (a derivative of putrefactive decomposition 
of albumin), hemosiderin becomes black, iron sulfid being formed." 2 
Grohe 3 believes that as a result of putrefaction iron is liberated from its 
compound with hemoglobin, so that when thus freed it readily combines 
with the hydrogen sulfid. 

Iron is the most important element to be considered in the list of 
factors causing the discoloration of this group of cases. It is the iron 
constituent of the red corpuscles which is the essential chromogenic 
factor from first to last in their cycle of color changes. 

The process of putrefactive decomposition consists of a series of 
chemical changes wrought out through the agency of microorganisms, 
involving the breaking down by successive stages of highly complex 
organic compounds and their resolution into compounds of much sim- 
pler constitution. It is not known to what extent this splitting up of 
the components of the pulp and its vascular elements is ultimately car- 
ried in the series of changes resulting in the permanent discoloration 
of the tooth. From what is known of the ultimate composition of the 
compounds involved it may, however, be safely inferred that, reduced 
to its lowest terms, the result, so far as pigmentation is concerned, would 
be the formation of iron sulfid, the elements of which, with the exception 
of some unimportant alkaline and earthy salts, are the only ones 
entering into the original compounds which are fixed and therefore 
capable of forming a stable residuum in the tubular structure of the 
dentin. While iron sulfid as such cannot be held wholly accountable 
for the final bluish-black color of a tooth which has reached the stage 

1 Ziegler, General Pathology, 1895. 2 Ibid. 3 Virchow's Archiv, Band xx. 



DISCOLORATION OF TEETH FOLLOWING DEATH OF PULP 523 

of permanent discoloration, the pigmentation is almost certainly due 
either to it or to some allied compound in which iron and sulfur, with 
some organic constituents, largely enter, and which by a further slight 
decomposition would yield true iron sulfid. 

The significance and importance of a recognition of the possible 
presence of the iron compound as a factor in tooth discoloration is 
further brought out in the study of bleaching methods. 

Discoloration of Teeth following Death of the Pulp Consequent upon its 
Exposure. — When death and decomposition of the pulp are consequent 
upon exposure of that organ, through caries or otherwise, to the irrita- 
tive influences of infective agents present in the oral secretions and 
food, or to thermal shock, etc., the putrefactive process involving the 
pulp tissues is modified in character and rapidity to a degree which 
may affect the character of the resulting discoloration. Thus, the 
yellowish or brownish discoloration so often seen in teeth whose pulps 
have been devitalized through systemic or traumatic causes, and which 
in many cases appears to be more or less permanent in character, is 
rarely observed in those teeth whose pulps have been devitalized through 
exposure by caries. 

In these latter cases the original suffusion of the dentin by hemo- 
globin has ordinarily not taken place and, moreover, the progress of the 
putrefactive process is comparatively rapid, the conditions being more 
favorable, so that the coloring matter of the blood is sooner reduced to 
its lowest terms in the scale of decomposition products, i. e., to the slaty 
blue or black pigmentation before noted. The pigmentation of the 
dentin in cases of pulp exposure with subsequent decomposition of that 
organ is due to the diffusion of some of the decomposition products 
of hemoglobin that have been formed in the pulp chamber and not in 
the tubuli as in the class of cases first considered. In addition to the 
increased rapidity of putrefactive decomposition incident to cases of dis- 
coloration following pulp exposure, another and important modifying 
factor in the process of discoloration is the ingress afforded to the oral 
fluids, food materials, and other adventitious substances which find 
their way into the mouth, and ultimately, through the open cavity of 
the tooth, to its pulp canal, and thence to the tubular structure of 
the dentin. These extraneous substances, in the course of time, 
may infiltrate the tooth structure, and while no especially noticeable 
or characteristic effect may be observed so far as color is concerned, 
yet they frequently exert an influence upon the coloration of the tooth 
which so alters its character as to render successful bleaching treatment 
extremely difficult and a resort to special methods or a variety of 
methods necessary. 

The introduction of fatty or oily substances or of astringent and 
coagulant matters, for example, may act upon the coloring matter in 
such a way as to "set" it permanently in the same manner that 



524 DISCOLORED TEETH AXD THEIR TREATMENT 

mordants form insoluble compounds or lakes with the dyestuffs used 
in the dyeing of textile fabrics. 

Another and important class of substances which frequently are the 
cause of staining of the tooth structure are metallic salts which are used 
in dental therapeutic treatment or are accidentally formed during the 
application of corrosive medicaments to the teeth, through the action of 
such remedies upon fillings in situ or upon the instruments by which 
the applications are made. For example, the use of iodin or sulfuric 
acid or other metallic solvents in connection with steel instruments 
and the subsequent use of medicaments containing tannin as an 
ingredient. 

The treatment of these conditions will be separately considered. 

Teeth Suitable for the Bleaching Operation. — In deciding upon the 
advisability of attempting the bleaching operation in any given case, 
the general conditions which determine the judgment of the operator 
with respect to all dental operations should govern his course. 

As all therapeutic and restorative measures in dentistry are a series 
of compromises with disease conditions or their sequelae, it is the duty 
of the operator under all circumstances to capitulate upon the basis of 
greatest advantage to the patient. Therefore, if discoloration of a tooth 
is practically the only factor in the problem presented by a given case, 
the effort should be made to restore the organ to its normal condition 
of color. The same rule should be applied to all cases of discolored 
teeth in which structural loss by caries or fracture has not been so great 
as to preclude a satisfactory restoration by proper filling or replace- 
ment of the lost structure by a porcelain inlay. The cases in which it 
is not advisable to attempt a bleaching operation are only those in which 
loss of structure is so extensive as to require a crowning operation. 

In the judgment of many operators it is considered useless to attempt 
the bleaching of any teeth excepting the incisors, because of the diffi- 
culty and length of time frequently required for the successful bleaching 
of canines, bicuspids, and molars, owing to the thickness of their walls 
and the consequent depth of the structure requiring treatment. It is 
also held to be useless to attempt the bleaching of teeth which have 
been discolored by metallic stains throughout their structure. The 
fallacy of such a view is self-evident when it is considered that if any 
portion of the dentinal structure of a discolored tooth is amenable to 
the bleaching treatment, its complete restoration is simply a question of 
continuance or repetition of the operation until the desired end is 
attained. 

With regard to discoloration by metallic stains, while teeth so affected 
present problems of great complexity, and require not only special 
study but the application of special methods of treatment based upon 
proper recognition of the chemical relationships involved between 
the nature of the stain and that of the agent used for its removal, the 



X ATI' RE OF PROBLEM IXYOLYED IN TOOTH BLEACHIXG 525 

attempt should be made in justice to the patient, even though ultimate 
failure result, in order that the necessity for destruction of the natural 
crown for the purpose of its replacement by an artificial substitute may, 
if possible, be postponed for as long a period as may be attainable. 

Nature of the Problem Involved in Tooth Bleaching. — The bleaching 
process is dependent upon a chemical reaction between a compound 
having color and some substance capable of so affecting its compo- 
sition that the color is discharged, or, in other words, of so affecting 
the integrity of the color molecule as to destroy its identity, which 
results in a loss of its distinguishing characteristic, viz., its color. 

The substances concerned in discoloration of tooth structure, as has 
been previously shown, are derived from the pulp and its vascular 
elements and the organic contents of the tubular structure of the den- 
tin, through the gradual putrefactive processes which become operative 
subsequent to the death of the pulp. These pigmentary products of 
pulp decomposition we know to be organic in character; and further, 
that they exhibit the property of color by virtue of definite conditions 
of molecular composition — that is to say, a certain arrangement of a 
definite kind and number of atoms has resulted in the formation of a 
molecule having its individual group of chemical and physical prop- 
erties, among which latter is a characteristic color. 

Whatever brings about an alteration in the composition of the mole- 
cule at once destroys the identity of the matter so treated. Hence, if 
we can act upon the coloring matter which gives rise to the staining of 
a tooth by means of an agent capable of effecting an alteration in the 
atomic arrangement of composition of the color molecule, we may expect 
incidentally to remove or discharge its color feature. 

Two general classes of substances have been successfully used as 
bleaching agents: First, those which act by virtue of their power to 
evolve oxygen in the active or nascent condition, and known as oxidiz- 
ing agents; second, those which act in an opposite manner by virtue 
of their strong affinity for oxygen, and which are called reducing agents. 
The oxidizing bleachers destroy the identity of the color molecule by 
seizing upon its hydrogen element to form water. The reducing agents 
act by removing the oxygen atom from the color molecule to form 
by-products depending upon the character of the reducing agent used. 

Chlorin and its cogeners iodin and bromin act as indirect oxidizing 
bleachers; the dioxids of hydrogen and of sodium are direct oxidizers. 
Potassium permanganate may also be classed with this group, although 
its successful use as a bleaching agent depends upon a subsequent treat- 
ment of the substance to be bleached with some solvent capable of 
removing the manganese dioxid formed as a by-product of the action of 
the permanganate. It has somewhat extensive and satisfactory use as 
an agent for bleaching sponges, and has been used for bleaching teeth, 
but is of greatly inferior value to other agents for the latter use. 



526 DISCOLORED TEETH AXD THEIR TREATMENT 

The only agent belonging to the group of reducing bleachers which 
has thus far been found available for bleaching teeth is sulfur dioxid, 
either in the gaseous condition or in aqueous solution. 

Chlorin as a Bleacher. — The general use of chlorin as a bleaching 
agent in the arts no doubt suggested its use in the treatment of tooth 
discoloration. Its introduction as a tooth-bleaching agent, as well as the 
assembling of the general principles of its use for tooth bleaching into a 
coordinated system, are due to Dr. James Truman, whose method depends 
upon the liberation of chlorin from calcium hypochlorite, commonly 
called bleaching powder or "chlorinated lime," in the pulp chamber and 
cavity of decay in the tooth. Chlorin is liberated from the bleaching pow- 
der by the action of dilute acetic acid; this taking place in contact with 
the discolored structure it is rapidly bleached as a result of the action of 
the chlorin upon the coloring matter contained in the dentinal tubules. 
Numerous modifications of this original method of bleaching tooth 
structure have been suggested, but, as the ultimate result in each is 
accomplished through the activity of chlorin, a rational understanding 
of the mode of action of chlorin in this relation is of importance as an aid 
to the intelligent use of those methods for tooth-bleaching which are 
dependent upon or owe their efficacy to that agent. 

Chlorin is an elementary gaseous body, greenish in color, soluble in 
water, having a disagreeable odor, intensely irritating to the air passages 
when inhaled, and poisonous when breathed in sufficient quantity. It 
has a strong affinity for all metallic bodies, entering into direct com- 
bination with a number of them, under favorable circumstances, with 
great energy — forming, as a rule, compounds that are soluble in water. 

One of its distinguishing features, and one which is directly concerned 
in its use as a bleaching agent, is its strong affinity for hydrogen. So 
strong is this affinity, that when a molecule of chlorin is brought into 
contact with a molecule of water under favorable conditions, the hydro- 
gen of the water molecule is seized upon by the chlorin to form chlor- 
hydric acid, and the oxygen is set free in the nascent state, a condition 
under which its oxidizing powers are exhibited in their greatest intensity. 
This powerful affinity of chlorin for hydrogen enables it to decompose 
many other hydrogen-containing molecules in a similar manner, form- 
ing chlorhydric acid and destroying the identity of the matter acted 
upon. 

It has been shown that all organic compounds which are the products 
of the vital processes of the animal body contain hydrogen as an impor- 
tant constituent. This applies also to the decomposition products 
whose presence in the tubular structure of the dentin is the cause of 
tooth discoloration. 

These organic stains exhibit the property of color by virtue of certain 
definite conditions of molecular composition; hence, if chlorin is caused 
to act upon the coloring matter which causes the staining of a tooth, 



PREPARATION OF TOOTH FOR OPERATIOX OF BLEACHING 527 

by seizing upon and combining with the hydrogen of the organic pig- 
ment, the identity of the compoimd as such is destroyed, and its char- 
acteristic feature, that of color, is lost. 

The principle here outlined is involved in what is termed the direct 
action of chlorin in bleaching. There is, however, another method by 
which chlorin is believed to act as a bleacher in which its function is 
indirect. 

In some cases it has been observed that chlorin fails to act except 
in the presence of moisture, and the rationale of this is that the bleach- 
ing under such conditions is effected by nascent oxygen liberated from 
the water molecule when the chlorin combines with its hydrogen 
to form chlorhydric acid: thus: CI, + H 2 = 2HC1 + O. That such 
is the nature of the process in many cases is a reasonable deduction 
from the behavior of chlorin under analogous conditions when it acts 
indirectly as an oxidizing agent. 

Whatever may be the exact nature of its ultimate action, it is to be 
borne in mind that its bleaching effect is due solely to the alteration 
which it makes in the composition of the color molecule, and that it 
has no solvent power whatever on the organic matter upon which it 
acts. It changes its characteristics, but does not remove it by solution. 
It should be also noted in this connection that the chlorin compounds 
of most of the metallic elements, especially when in dilute solution, are 
almost colorless as compared with many of the other metallic com- 
pounds — the oxids and sulfids, for example. Hence it is that when 
stains owe their color to the presence of certain organic compounds 
with some of the metals, or even when the coloration is due to decom- 
position products of hemoglobin, the color may readily be discharged 
by chlorin; but if the iron chlorid thus produced by the action of chlorin 
on the iron constituent of the hemoglobin remains in the tooth 
structure it is gradually decomposed and new combinations of it are 
liable to occur, which result in a return of the discoloration. 

All tooth-bleaching methods should aim not only to discharge the 
color by suitable chemical means, but should go farther than this. and. 
as far as it may be possible to do so, remove all organic debris and 
by-products of the bleaching process from the tubules, for as long as 
any remain the tendency to a return of the discoloration is always a 
possible and indeed probable menace to the complete and permanent 
success of the operation. 

When the tubular contents cannot be successfully removed, the 
tendency to a return of discoloration may be combated by hermetically 
sealing the tubular orifices with an impermeable resinous varnish or by 
permanently coagulating them. This feature is described more fully in 
relation to the details of the bleaching procedure. 

Preparation of the Tooth for the Operation of Bleaching. — Certain general 
details are necessary to be observed in the preparation of teeth for the 



528 DISCOLORED TEETH AND THEIR TREATMENT 

bleaching operation, whatever may be the method of treatment 
employed. 

Appropriate treatment for the removal of all septic matter from the 
pulp chamber and canal, and for the relief of any existing condition of 
irritation of the pericemental membrane and tissues of the apical region, 
should have been carried out and the tooth brought to the condition in 
which permanent closure of the apical foramen of the root may be safely 
performed. 

The rubber dam should be adjusted with special care and only 
include the tooth to be bleached. If two adjoining teeth are to be 
bleached, they may both be isolated by the dam; but in no case should 
one or more adjacent normal teeth be included with the tooth to be 
bleached. While the inclusion of teeth adjacent to the one which is 
the subject of any ordinary dental operation is in all cases desirable, 
there are good reasons why such a plan should not be pursued in the 
bleaching procedure. The chemicals used for the purposes may possibly 
have some disintegrating or solvent action upon the enamel structure, 
and such action, should it occur, should be confined strictly to the tooth 
undergoing treatment and held within the limits of safety by close 
observation and appropriate treatment, which conditions cannot be as 
thoroughly controlled and the process as satisfactorily managed when 
several teeth are included within the territory of operation. 

Furthermore, as nearly all of the bleaching agents used or those 
which are employed as adjuvants to the process have a more or less 
irritative or escharotic effect upon the soft tissues of the mouth, extra 
precautions must be taken, in adjusting the dam, against leakage at its 
attachment to the cervix of the tooth. As the chances of leakage are 
greatly multiplied when several holes are punched in the dam for adjust- 
ment to as many teeth, it is for this reason also that no other than the 
tooth to be treated should have the dam adjusted to it. 

Supposing the tooth to be an upper incisor, the dam should be slipped 
over it and the margin of rubber encircling the cervix should be gently 
carried under the free margin of the gum either by means of a small 
flat burnisher of suitable angle and curvature, or by means of a waxed 
floss-silk thread. One or two turns of a ligature should then be thrown 
around the cervix below the dam to hold it securely in place. The 
dam may be fixed with greater security, especially as against any 
accidental traction made upon it during the operation, by fastening it 
with a ligature made as follows and thrown around its cervix: 

A piece of waxed ligature silk about eighteen inches in length has 
a large knot tied at about its middle portion by making six or eight 
turns of the thread loosely around the end of the index finger of the 
left hand. Upon withdrawing the finger a series of loops are had through 
which one of the free ends of the thread is now passed, as in making 
the first half of a flat knot, as illustrated in Fig. 568. By drawing upon 



PREPARATION OF TOOTH FOR OPERATION OF BLEACHING 529 

the free ends of the thread until all of the loops are closed upon them- 
selves, a hard knot of more or less spheroidal shape is formed about 
midway between the ends of the ligature. The ligature so prepared 
is placed around the tooth in such a manner that the knot as described 
shall be located upon and at the middle portion of the palatal cervical 
margin. A half -knot is then made by tying the ligature in front so that 
it shall rest directly opposite the palatal knot, viz., at the middle portion 
of the labial cervical margin. The ligature is drawn into fairly close 
contact with the tooth, and, with both ends held firmly in the left 
hand and drawn somewhat tense, the portion encircling the tooth is 
firmly but gently forced up against the rubber dam and gingival margin, 
the ligature at the same time being drawn tightly until the anatomical 
constriction of the tooth at its cervix will serve to hold it from slipping 
downward, especially upon the palatal aspect of the tooth. 

Fig. 568 




When the ligature is found to be securely placed as described, the 
knot upon the labial aspect is completed and further enlarged in bulk 
by re-tying the thread four or five times. The free ends of the ligature 
should then be cut off close to the knot. As an additional safeguard 
against leakage of irritating bleaching agents through the cervical 
attachment of the dam, and out upon the soft tissues, it is well after 
making the tooth perfectly dry to paint the ligature and a narrow band 
of its adjacent territory with chloropercha, which after evaporation of 
the solvent will effectually prevent any accident from leakage. 

The placing of a large knot upon the palatal aspect at the cervical 
margin has another decided advantage in that it not only holds the dam 
more securely against slipping downward, but holds it away from the 
palatal surface, which is ordinarily the point of entrance to the pulp 
chamber and canals in these cases. The point of canal entrance may, 
however, be through a proximal cavity, if such a one afford sufficient 
access. 

The canal filling in all cases of bleaching without exception should 
be gutta-percha. No other material used for canal filling possesses the 
generally desirable qualities needed for that purpose in this class of 
cases. The extent of the canal filling should include one-third, or at 
least not over one-half, of the distance from the apex. A considerable 
portion of the canal beyond the level of the gingival margin is thus 
left unfilled in order that the coronal end of the root may be bleached 
34 



530 DISCOLORED TEETH AND THEIR TREATMENT 

as well as the tooth crown. This is especially necessary when more 
or less recession of the gum from its normal attachment has occurred, 
leaving the cervical cementum exposed to the action of the oral fluids, 
food, etc., which have a tendency to cause discoloration of the exposed 
root tissue. 

The root being filled as directed, all fillings wherever existent in the 
tooth should be removed. This is a preliminary procedure which 
should not be omitted in any case, but where any bleaching method is 
used which involves the employment of chlorin as the active agent it 
becomes imperatively necessary for reasons which are explained in 
connection with the description of the chlorin methods. Aside from, 
other considerations, the removal of all fillings preparatory to the 
bleaching operation has a decided value in facilitating the process by 
exposing an increased area of the dentinal structure and thereby permit- 
ting the action of the bleaching agent over a larger territory of ingress. 

When all fillings or softened tooth structure have been removed, as 
well as all septic and extraneous matter of whatever character, by 
mechanical process, the tooth should be washed thoroughly with dilute 
ammonia water, or better with a hot solution of borax in distilled water 
in the proportion of 3 j to f 5 j. The object of this treatment is to remove 
by saponification and solution all fatty matters which may obstruct 
the ingress of the bleaching agent into the dentinal structure. 

In nearly all cases where discoloration has occurred from a decom- 
posed pulp, and where the canals and pulp chamber have been left 
untreated, there will be observed, on opening into such a pulp chamber 
for the first time, a dark layer of oily or greasy material lining its walls. 
The thorough removal of this dark layer should be effected prior to 
any attempt at bleaching, as it appears to prevent the ingress of the 
bleaching agent into the dentinal structure. The most satisfactory 
method for removing the dark greasy layer is by the use of suitable 
instruments — either properly shaped spoon or hoe excavators or round 
burs in the engine. The thorough removal of this layer necessitates 
free access to the pulp chamber, which should be, as a general rule, 
obtained by means of an ample opening upon the lingual aspect of 
the tooth in the case of incisors, and through the morsal surface in 
bicuspids, etc. 

Having by mechanical means and through the agency of borax or 
ammonia and hot distilled water effected a thorough cleansing of the 
interior portion of the tooth, it should next be dried to the extent of 
having all superfluous moisture removed, and it will then be in condi- 
tion for the application of whatever method of bleaching may be chosen 
for the particular case in hand. When sodium dioxid or Schreier's 
kalium-natrium with hydrogen dioxid are to be used as the bleaching 
agents the preliminary saponification of the canal contents with 
ammonia or hot borax solution becomes unnecessary. 



TRUMAN'S METHOD 531 

Truman's Method. — This, as before stated, was the first method 
successfully employed for bleaching teeth. It consists in liberating 
chlorin from ordinary chlorinated lime by means of a weak acid in 
the pulp chamber of the tooth. Any acid will effect the liberation of 
chlorine from the bleaching powder, but acetic, tartaric, or oxalic are 
generally used. Care must be observed in selecting a good quality of 
bleaching powder, as that substance rapidly undergoes decomposition 
spontaneously, especially in a moist atmosphere. Good chlorinated lime 
is a dry powder having a strong odor of chlorin. If it is moist or pasty, 
and has but a feeble odor, it should be rejected as worthless. Brands 
of bleaching powder dispensed in metallic packages should not be used, 
as they are invariably contaminated with metallic chlorids due to the 
slow action of the contents upon the containing package. This is par- 
ticularly the case when sheetiron boxes are used. The return of dis- 
coloration in many cases after bleaching by the Truman method is 
undoubtedly due to the use of bleaching powder so contaminated. 
The powder dispensed in glass bottles or in paraffined paper cartons 
is more reliable. 

Its application to the tooth may be effected in several ways: 

(a) By packing the dry powder in the pulp chamber and then moist- 
ening the latter with the acid. 

(b) By mixing the powder with sufficient distilled water to make a 
coherent mass which is more easily manipulated, then packing it in the 
pulp chamber and applying the acid. 

(c) By first moistening the interior of the tooth with the acid, next 
dipping the instrument into the powder and then into the acid, each 
time carrying the mixed materials into the tooth until the desired 
change of color is produced. 

Probably the most satisfactory method is to pack the dry powder 
into the tooth and apply the acid to it, after which immediately seal the 
cavity with a single pellet of gutta-percha. By using a 50 per cent, 
solution of acetic acid the evolution of chlorin will take place with a 
satisfactory degree of uniformity, and not so rapidly as to interfere with 
its penetration throughout the discolored tubular structure of the dentin. 
The bleaching mass may be sealed in place by means of zinc oxyphos- 
phate if desired, but it is usually unnecessary to use anything other 
than gutta-percha or one of the soft temporary stopping materials for 
this purpose. 

The case may be dismissed for one or two days and the treatment as 
outlined repeated at similar intervals until the tooth is restored to 
normal color. 

The instruments used in connection with this process should be of 
vulcanite, bone, ivory, or wood. Upon no consideration should steel, 
gold, or platinum instruments be used, as chlorin acts directly upon 
each of these metals, forming soluble chlorids, which if carried into the 



532 DISCOLORED TEETH AND THEIR TREATMENT 

tooth structure will give rise to a permanent staining of most intract- 
able character. The only metals which may be safely used in connec- 
tion with any chlorin process of bleaching are zinc and aluminum, 
the chlorids of which are colorless, but, nevertheless, they are objection- 
able for the reason that both are coagulant and color mordants. 
Aluminum instruments for the purpose may be quickly improvised out 
of wire or heavy plate. Gold instruments have been recommended, 
but they are open to the very grave objection of forming a chlorid by 
direct combination with chlorin, which salt is one of the most important 
staining media known to the histologist; as a matter of fact, the writer 
has seen several cases where a permanent purple staining of the tooth 
has resulted from neglect to remove gold fillings before applying the 
chlorin method of bleaching, and there is certainly no reason why the 
same result should not follow the using of gold instruments in the same 
connection. 

When the tooth has been restored to its proper color it should be 
thoroughly washed with liberal quantities of very hot distilled water, 
dried out with bibulous paper, and thoroughly desiccated with a current 
of dry hot air, after which the canals, pulp chamber, and cavities 
should be filled with zinc oxy chlorid. 

The final filling of the cavities of entrance and of decay should be 
postponed until, by a lapse of considerable time, the permanence of the 
operation has been established. This probationary period may with 
advantage be prolonged to four or six months. 

The final washing of the tooth with hot distilled water previous to 
the insertion of the zinc oxychlorid filling is a feature of the opera- 
tion which requires special care and attention. As left after the appli- 
cation of the bleaching agent, the pulp chamber and canals and denti- 
nal structure are filled with free chlorin in solution, iron chlorid from 
the combination of the chlorin with the iron element of the color mole- 
cule, calcium acetate, or other salt of calcium, depending upon the 
nature of the acid used in the process, and probably some undecom- 
posed bleaching powder. These substances should be thoroughly 
removed by the hot-water douche. At least a pint of water should be 
strongly injected into the interior of the tooth, by means of a large bulb 
syringe or other convenient means, before the dam is removed. A thick 
towel held in close proximity to the tooth will catch the water as it 
returns from the tooth and protect the clothing of the patient. Distilled 
water should in all cases be used for this irrigating douche, as river 
water and many other specimens of water from natural sources contain 
iron in solution, which could readily become a contaminating factor, 
leading to subsequent return of discoloration. 

Zinc oxychlorid is selected as the permanent filling for the pulp 
chamber, for the reason that it is necessary so to act upon the bleached 
organic residuum in the tubular structure as to prevent any alteration 



WRIGHT'S METHOD 533 

of its character which may result in the production of a subsequent 
coloration. Zinc chlorid possesses the property of converting many 
organic substances into unalterable compounds by its coagulant action, 
thus tanning or mummifying animal tissue and preserving it indefi- 
nitely. A mass of zinc oxy chlorid, before it sets — i. e., before chemical 
combination takes place between the zinc oxid powder and the zinc 
chlorid liquid, is functionally free zinc chlorid — and, as a matter of 
fact, the properties of zinc chlorid are manifested by such a mass for a 
considerable period of time after the mass has apparently set. When 
introduced into the pulp chamber and canal, its action upon the organic 
debris in the tubuli is as stated, and the material, if the operation has 
been successfully performed, is effectually prevented from further alter- 
ation, upon which condition the permanence of the operation depends. 

Another method for preventing subsequent alteration of the bleached 
organic debris in the tubular structure is to desiccate the tooth thor- 
oughly by means of the hot-air blast and saturate the dentin with some 
insoluble resinous varnish, such as copal ether varnish, or, what is still 
better, the solution of trinitrocellulose in methyl alcohol and amyl 
acetate, known in commerce as "kristaline," or at the dental depots as 
"cavitine." The pulp chamber and canals may then be filled with any 
suitable filling. 

As between the zinc oxychlorid filling and the varnish lining, the 
choice in general should be of the former. The varnish lining is adapt- 
able more especially to cases of long standing, where complete liquefac- 
tion of the tubular contents has left them practically empty, and where, 
as a consequence, there is nothing upon which zinc chlorid can exert its 
coagulating effect. 

Other Chlorin Methods. — The solution of chlorinated soda known 
as Labarraque's solution, or Liquor soda? chloratae U. S. P., may be 
applied to the previously desiccated tooth structure until the dentin 
is saturated with the solution, after which an application of a dilute 
acid is made which liberates chlorin. The chemical principles involved 
are exactly analogous to those upon which the method with bleaching 
powder depends, the only difference being that the source of the active 
agent, chlorin, is in one case its calcium compound, which is a dry 
powder, and in the second case the analogous soluble sodium compound 
of chlorin is the material from which the active agent is evolved. 

The precautions necessary to be observed are exactly the same as 
those required in Truman's method, already described. The results 
obtained by this process are not as thorough or as satisfactory as by the 
Truman method. 

Chlorin per se has been used for tooth bleaching, and was the basis 
of a method devised by Dr. E. P. Wright, of Richmond, Va. 

Wright's Method. — This involved the use of a complicated apparatus 
by which a glass vessel of about a half-liter capacity, and filled with 



534 DISCOLORED TEETH AND THEIR TREATMENT 

chlorin previously prepared in the laboratory, was connected by means of 
a doubly perforated rubber stopper and two pieces of rubber tubing with 
a glass adapter, around the open end of which was tied the rubber dam 
encircling the tooth to be operated upon. About midway of the length 
of one of the rubber tubes connecting the chlorin reservoir with the 
rubber dam was interposed an ordinary syringe bulb, so arranged with 
hard-rubber valves that by repeatedly compressing and relaxing it the 
chlorin would be drawn from the reservoir and injected through a glass 
delivery jet into the pulp chamber. Return of the gas to the reservoir 
was provided for by the second piece of rubber tubing first alluded to. 
In this way a continuous jet of chlorin was thrown into and about the 
tooth, which, by means of the rubber dam, was placed in a close cham- 
ber forming a part of the apparatus; none of the gas could escape into 
the surrounding atmosphere. The complexity of the apparatus was 
a formidable obstacle to the general use of the method, and it was 
abandoned, though the results were in many cases very satisfactory. 

Iodin. — Reference has previously been made to iodin as a bleaching 
agent. Its chemical action is quite analogous to that of chlorin, though 
less energetic. In slight discolorations, however, iodin may often be 
used to considerable advantage by simply saturating the dentin with an 
alcoholic solution of iodin — e. g., the official 7 per cent, tincture — until 
the tooth structure is stained a characteristic yellow. The cavity is 
then sealed temporarily with a gutta-percha filling and the case dis- 
missed for twenty-four hours, at the expiration of which period a marked 
improvement in color will be observed. The same precautions as with 
the use of chlorin in regard to the removal of metallic fillings and the 
avoidance of contact with metallic instruments is necessary in the 
use of iodin for bleaching purposes. 



THE DIOXID BLEACHING METHODS 

Bleaching by Means of the Dioxid of Hydrogen and of Sodium. — The 
commercial introduction of solutions of hydrogen dioxid marked a 
new era in the operation of bleaching discolored teeth. The bleaching 
property of hydrogen dioxid had been known to chemists for many years, 
but the application of this property to tooth-bleaching dates from the 
medicinal use of hydrogen dioxid solutions for the treatment of puru- 
lent conditions of the pulp canal and about the roots of teeth. When 
applied in the canals of discolored and infected teeth it was observed 
that a noticeable bleaching of the discolored structure resulted. The 
hint thus given was further studied until it was found that under proper 
conditions the whole structure of a discolored tooth might be success- 
fully restored to normal color. 

The earlier preparations were found to be lacking in strength; aqueous 



THE DIOXID BLEACHING METHODS 535 

solutions containing more than 3 or 4 per cent, of absolute hydrogen 
dioxid were found to be too unstable to keep for any length of time, 
and hence were unreliable. The problem of securing a stable high- 
percentage solution of the dioxid was solved by using ether as a men- 
struum, and the 25 per cent, solution of hydrogen dioxid, sold as 
"caustic pyrozone," is now generally used when hydrogen dioxid is 
employed as a bleaching agent in connection with discolored tooth 
structure. 

Subsequent to the introduction of the pyrozone preparations, the 
firm of Merck has produced a 100- volume solution of hydrogen dioxid 
under the trade name of Perhydrol, which is the most active and efficient 
of the hydrogen dioxid preparations as tooth -bleaching agents. 

Hydrogen dioxid, H 2 2 , belongs to the class of "oxidizing bleachers," 
and owes its activity in this respect to the weak state of chemical 
combination in which one of its atoms of oxygen is bound to the water 
molecule. Many substances serve to disrupt the compound and liber- 
ate one of its oxygen atoms. In contact with pus, blood, inspissated 
mucus, albumin, and in fact almost every kind of dead organic matter, 
its decomposition takes place, evolving oxygen and decomposing the 
organic matter either wholly or in part. Hydrogen dioxid does not 
bleach all of the decomposition products of hemoglobin with equal 
facility. It quickly removes the pink discoloration following the initial 
extravasation of hemoglobin into the dentin, but when the brown stage 
has been reached, indicative of the formation of hematin, its action is 
but slight. Later, however, it bleaches more readily. The refractory 
nature of hematin with respect to hydrogen dioxid has been experimen- 
tally tested upon the substance out of the mouth. 

It is important to note that all acids promptly convert hemoglobin 
into hematin, which is highly resistant to the action of hydrogen dioxid; 
therefore, whenever hydrogen dioxid is used to bleach a tooth in the 
primary or pivot stage of discoloration the hydrogen dioxid should be 
made alkaline with sodium carbonate or hydroxid to neutralize at least 
its usual slight acidity, otherwise its acid content will act upon the 
hemoglobin, converting it into hematin, and thus set the color in such 
a way as to be invulnerable to the action of the hydrogen dioxid. 

In bleaching discolored teeth with hydrogen dioxid, perhydrol or the 
ethereal 25 per cent, solution known as pyrozone is directly applied to 
the internal portions of the tooth upon small pledgets of cotton or cotton 
wisps rolled upon a fine flexible canal instrument. After each appli- 
cation the menstruum is evaporated by blasts of warmed air from a 
hot-air syringe, and the applications similarly made are repeated until 
the desired effect is produced. It has been found in practice that 
more rapid and permanent effects are produced when the solution 
is rendered alkaline. This may be readily done by the addition of a 
few drops of liquor ammonia? fortior or by a solution of one of the 



536 DISCOLORED TEETH AND THEIR TREATMENT 

caustic alkalies, e. g., sodium or potassium hydroxid or sodium dioxid. 
A very satisfactory method of securing the alkaline effect in this pro- 
cess is that suggested by Dr. D. N. McQuillen. His method is to 
first treat the pulp chamber and canals with applications of Schreier's 
Kalium-natrium preparation, and after the debris from its action has 
been mechanically removed with instruments and cotton twists, with- 
out washing the canal, an application of pyrozone is made. The bleach- 
ing action follows with great rapidity, and has apparently greater 
permanence than when the pyrozone is used alone. In cases in which 
the action proceeds very slowly — for example, when at the end of a thirty 
minutes' continuous treatment the bleaching is not complete — it is well 
to seal an application of pyrozone upon cotton in the canal and allow it 
to remain for twenty-four hours, when a second treatment will usually 
complete the operation. 

In this, as in all bleaching operations, it is advisable to fill the tooth 
temporarily with some easily removable filling in order to test the per- 
manence of the operation, and after the lapse of a reasonable time, if 
there is no tendency to a return of the discoloration, the canals and 
cavity may be permanently filled. 

Harlan's Method. — This consists in acting upon hydrogen dioxid by 
aluminum chlorid. The aluminum salt is packed in the cavity and 
moistened with the dioxid. The technique of the Drocedure is the same 
as for the methods already described. This process was originally 
classified with the chlorin methods, as the decomposition was supposed 
to take place according to the following equation : 

A1 2 C1 6 + 3H 2 2 = A1 2 3 + 3H 2 + 6C1. 

Experimental study of the reaction between aluminum chlorid and 
hydrogen dioxid by the writer developed the fact that oxygen and no 
chlorin was given off, and that the aluminum chlorid was unaltered 
during the process. Hence it was discovered that the reaction was 
simply due to a catalytic action of the aluminum salt (a property 
which in this relation it shares in common with many other metallic 
salts), whereby nascent oxygen is liberated from the hydrogen dioxid. 
The process, therefore, has no greater value than those in which hydro- 
gen dioxid is directly applied. The aluminum chlorid, being an active 
coagulant, is contraindicated as a factor in the bleaching process until 
a point had been reached where a coagulant is needed as a fixative after 
the bleaching has been effected. 

The Sodium Dioxid Method. — Sodium dioxid, Na 2 2 , is the chemical 
analogue of hydrogen dioxid, and like the latter is characterized by 
the readiness with which it parts with its atom of loosely combined 
oxygen under similar circumstances. The essential difference in its 
properties is the character of its by-product after its decomposition 



THE DIOXID BLEACHING METHODS 537 

has taken place. Itself a strong caustic alkali, it still retains its alka- 
line and caustic properties after the loss of one of its atoms of oxygen, 
becoming Na 2 0, which in combination with water is ordinary sodium 
hydroxid or caustic soda. This substance, as well as the sodium dioxid, 
has not only a saponifying property for all of the vegetable and animal 
oils and fats, but also a solvent action upon animal tissue. This property 
is of great value in removing from the dentin structure all of the con- 
tained organic matter, whether normal or in a state of decomposition. 
Having the oxidizing and consequently the bleaching quality in addi- 
tion to its solvent and saponifying properties, it is, therefore, one of the 
most valuable bleaching and detergent agents at our command. The 
substance is dispensed as a yellowish-white powder in tin cans or glass 
bottles hermetically sealed, as it is very hygroscopic, and after twenty- 
four hours' exposure to moist air absorbs nearly its own weight of water; 
it also loses much of its activity. 

For use as a bleaching agent, it is applied to the dentin in saturated 
solution. In making the solution, special care is necessary in order to 
avoid elevation of temperature, by reason of the energy with which it 
enters into combination with the water. If the solution is allowed 
to become heated in the making, decomposition of the compound with 
loss of oxygen occurs, and its bleaching power is destroyed. The solu- 
tion is best made by pouring into a small beaker, of about one ounce 
capacity, about two drams of distilled water, and immersing the 
beaker in a larger vessel or dish containing iced water or pounded ice. 
The can containing the dioxid powder should then have its lid per- 
forated with a number of small holes similar to the lid of a pepper 
shaker, and the powder be slowly dusted into the distilled water in the 
small beaker; or the powder may be gradually dropped into the water 
by tapping it from the point of a knife or spatula. The powder is 
added to the water until the solution assumes a semi-opaque appearance, 
indicating the point of saturation. 

On removing the beaker from the cooling mixture, the dioxid solution 
will in a few minutes assume a transparent, straw-colored appearance 
and is ready for use. 

The applications are to be made similarly to the hydrogen dioxid 
applications, but upon asbestos fiber instead of cotton, as the latter is 
acted upon by the sodium dioxid and converted into a glue-like mate- 
rial, amyloid, which is difficult to remove and interferes with the suc- 
cess of the operation. 

After the dentin, which should have been previously desiccated, is 
thoroughly saturated with the dioxid solution, an application of 10 per 
cent, sulfuric acid should be made, which neutralizes the strong alkali, 
forming sodium sulfate and hydrogen dioxid, thus: 

Na 2 2 + H 2 S0 4 = Na,S0 4 + HA. 



538 DISCOLORED TEETH AND THEIR TREATMENT 

The reaction is usually attended with some effervescence, which, taking 
place in the tubular structure of the dentin, mechanically forces out its 
contents and thus exerts a detergent action upon it. The tooth should 
now be washed with hot distilled water in copious quantity and the 
dioxid application repeated, omitting the subsequent treatment with 
acid, but washing again thoroughly with the hot water. 

Sodium dioxid solution, as prepared for bleaching, may be applied 
to the pulp chamber and root canal without the preliminary treatment 
required where other bleaching agents are employed. It is without 
harmful irritative action upon the apical tissues unless used in excess 
or forced through the foramen by careless manipulation. It is a power- 
ful germicide and disinfectant, and therefore peculiarly suited to the 
treatment of putrescent cases, which by its action are rendered sterile 
and aseptic as well as bleached at one operation. Its saponifying and 
solvent properties completely remove the greasy dark layer of decom- 
posed material which is found lining the pulp chamber and canals 
alluded to on page 530, so that the use of the sodium dioxid method 
makes unnecessary the application of borax or ammonia for its removal 
as a preliminary. When used for its sterilizing property the foramen 
should be allowed to remain unsealed until after the bleaching operation 
has been completed. It sometimes happens that the improvement in 
color following the application of the dioxid methods is only partial, 
and the result falls short of restoration to normal; or, in other words, 
the bleaching reaches a certain point beyond which the color resists the 
further action of the bleaching agent. In such cases the decomposition 
of the color molecule has probably resulted in the formation of iron 
oxid as an end product. In practice this residual discoloration can 
generally be removed by treatment with oxalic acid. A small crystal 
is to be sealed in the moist pulp chamber for twenty-four hours, and 
afterward washed out with a copious irrigation of hot distilled water. 

The sodium dioxid method removes more completely than any 
other the tubular contents, and the result is unique from the fact that 
not only is the tooth restored to normal color, but to normal trans- 
lucency; the opaque white effect resulting from other methods of 
bleaching is due to the bleached organic debris remaining in the tubuli, 
but by the solvent action of the strong caustic alkali this is removed. 
The final treatment of the tooth is the same in this as in other methods, 
though the dentin should be desiccated and saturated as thoroughly 
as possible with an unalterable varnish before the final filling is inserted. 

The Sulfur Dioxid Method. — Reference has already been made to 
sulfur dioxid as the single example of the reducing type of bleaching 
agent. Its activity is due to its affinity for oxygen, and it bleaches 
by seizing upon and combining with that element of the color molecule, 
thus destroying its identity and consequently its color. Attempts have 
been made to utilize the bleaching property of sulfur dioxid in the 



CATAPHORIC BLEACHING OF TEETH 539 

treatment of discolored teeth by direct applications of the solution of the 
gas in water and by igniting small quantities of sulfur in the root canal 
by means of the electrocautery wire. These methods have, however, 
proved inefficient. The gas may be successfully used in bleaching teeth 
by evolving it from its compounds placed in the cavity and root canal 
in a manner analogous to that employed in the Truman chlorin process, 
already described. For this purpose the writer's method may be con- 
veniently employed : 100 grains of sodium sulfite and 70 grains of boric 
acid are separately desiccated and afterward ground together in a 
warm dry mortar. The powder is then to be transferred to a tightly 
stoppered bottle. For bleaching purposes the powder is packed into the 
root canal and cavity of the tooth, and then moistened with a drop of 
water and the cavity immediately closed as tightly as possible with a 
stopping of gutta-percha previously prepared and warmed. A reaction 
ensues between the boric acid and sodium sulfite whereby sulfur dioxid 
is liberated, thus: 

2H 3 B0 3 + 3Na 2 S0 3 = 2Na 3 B0 3 + 3H 2 + 3S0 2 . 

The process is effective in many cases in which the chlorin methods 
have failed, but is slow in its action, and is largely superseded by the 
hydrogen dioxid and sodium dioxid methods. 



CATAPHORIC BLEACHING OF TEETH 

It has been found that aqueous solutions of hydrogen dioxid may be 
carried into the dentinal structure with great ease by the cataphoric 
action of the continuous current. The appliances necessary for tooth- 
bleaching operations by this means are practically the same as those 
required in the treatment of hypersensitive dentin. The resistance 
offered by the hard structures of the tooth is much greater after loss 
of the tooth pulp, requiring a much higher voltage pressure to drive the 
bleaching agent into the tissue. While in some cases 25 to 30 volts will 
be all that is necessary, some cases will require as high as 60 volts to 
carry 1.5 milliamperes of current through the dentin. The ethereal 
solution of hydrogen dioxid has been found to oppose too great resistance 
to the current, but the aqueous solution, containing a slight addition of 
some salt to increase its conductivity, is entirely manageable. 

A 25 per cent, aqueous solution of hydrogen dioxid may be quickly 
made by shaking together in a test-tube one volume of water and two 
volumes of 25 per cent, pyrozone. The H 2 2 dissolves in the water, 
and the ether of the pyrozone may be removed by pouring the mixture 
into a small evaporating dish of porcelain or glass and gently heating it 
over a water bath until all of the ether has evaporated. The addition 



540 DISCOLORED TEETH AND THEIR TREATMENT 

of a small quantity of sodium acetate or sulfate will greatly diminish 
the resistance of the solution to the passage of the current. 

With the tooth isolated by the rubber dam and having received the 
treatment preliminary to bleaching, as already described in detail, the 
aqueous solution of H 2 2 is dropped upon cotton within the tooth 
cavity and a platinum needle anode is applied in contact with it. The 
cathode may be a sponge electrode moistened with salt solution and 
held in the hand or applied to the cheek or neck. The hand, however, 
is preferable because of the amount of voltage required in the operation. 
Great care must be exercised that the external surfaces of the tooth are 
kept dry, so that short-circuiting of the current may not take place. In 
some cases a more rapid effect is obtained by making contact of the 
cathode pole through a needle electrode upon the external surface of the 
tooth, and with the anode applied to the pyrozone solution on cotton 
within the tooth. The cotton must at all times be kept wet with the 
solution. 

The arrangement of the electrical terminals with respect to the 
bleaching operation is both theoretically and practically correct as de- 
scribed, viz., the flow of current should be from the anode point through 
the bleaching solution and tooth and the body of the patient to the 
cathode. In practice it has been found in some cases which have failed 
to bleach with the elements arranged in the series as stated, that upon 
reversing the poles and direction of current flow the bleaching has 
rapidly followed. The explanation of this apparent paradox is that 
by the application in normal order H 2 2 was first carried into the 
tubular structure, and the reversal of the current has acted upon the 
tubular contents now saturated with the dioxid, and by its propulsive 
as well as electrolytic effect removed the pigmentary matter pulpward 
from the tubuli. Bleaching with reversed poles would be impossible 
without previous saturation of the dentin by the dioxid solution. 

Dr. M. W. Hollingsworth has devised an ingenious apparatus for 
cataphoric bleaching which is of special value, as it makes possible 
the enveloping of the entire tooth with the bleaching fluid, in which 
it is immersed as in a bath. The appliance is shown in situ in 
Fig. 569, and consists of a thin vulcanized caoutchouc bulb shaped 
like the bulb of a medicine dropper. Through a perforation at its 
rounded end, made with the ordinary rubber dam punch, the tooth 
is slipped by mounting the bulb on the applicator (Fig. 570), and forcing 
it over the tooth as though it were a rubber dam. A glass tube is then 
attached to the open end of the bulb, and to the glass tube is connected 
a spiral platinum wire electrode (Fig. 571). Before the electrode is 
attached the bulb and glass tube are completely filled with the aqueous 
pyrozone solution by means, of a duplex syringe (Fig. 572), the lower 
and larger bulb of which exhausts the contained air in the apparatus 
and the smaller thumb bulb injects the bleaching solution into the 



CATAP HO RI C BLEACHING OF TEETH 



541 



Fig. 569 




Hollingsworth'B device 



for applying the bleaching agen 



Fig. 570 



t to the tooth. 




Duplex syringe. 



542 DISCOLORED TEETH AND THEIR TREATMENT 

exhausted apparatus. Connection is now made with the source of cur- 
rent as usual, and the bleaching is very rapidly effected. Dr. Hol- 
lingsworth recommends the addition of about 1 per cent, of zinc sulfate 
to the aqueous pyrozone solution, which not only diminishes the resist- 
ance to the passage of the current, but has a coagulating effect upon 
the bleached organic matter, which gives it translucency and greatly 
enhances the permanency of the operation. The results obtained by 
this method are extremely satisfactory. 

Actinism as an Adjuvant to the Bleaching Process. — The efficiency of 
sunlight as a bleacher has long been known and practically utilized 
in the bleaching of cotton and linen fabrics, both on a commercial scale 
and in domestic practice. The tendency of vegetable and some mineral 
coloring matters to fade in the sunlight is a phenomenon of common 
observation. It is known that the power possessed by light of bringing 
about chemical changes is a property which is not shared equally by all 
parts of the solar spectrum, but is most marked in the violet and ultra- 
violet rays when the undulations are of highest frequency. Advantage 
has been recently taken of the actinic factor of light as an adjuvant 
to the tooth-bleaching 'process in connection with hydrogen dioxid by 
Dr. Pfliiger, of Hamburg. The method consists in making an applica- 
tion of perhydrol on cotton to the pulp chamber of the discolored tooth 
and also coating the crown with the bleaching agent, then concentrating 
with a double convex lens a beam of light from an electric arc lamp 
upon the tooth, which in the course of from fifteen to thirty minutes is 
restored to its normal color in cases amenable to the bleaching action 
of the dioxids. Experiments by Dr. Pfliiger have shown that when the 
actinic effect of the light is used the action of the hydrogen dioxid is much 
more rapid and efficient than when used without the light. Tests of 
actinic rays with bleaching agents other than hydrogen dioxid have 
not as yet been made, but the use of the rays in such connection would 
seem to be promising of usefulness. 



BLEACHING METHODS FOR SPECIAL STAINS 

Pulpless teeth are specially liable to discoloration from external and 
accidental causes. If decayed and the cavity has remained unfilled for 
a length of time, many substances which find their way into the oral 
cavity either as food or as medicine may produce discoloration when 
absorbed by the tooth through the open cavity walls. 

Metallic salts are particularly apt to cause such staining by reaction 
with the sulfids with which the dentin structure is usually saturated 
during decomposition of its organic contents. Many of the medica- 
ments used in pulp-canal treatment, or even for hypersensitive dentin, 
may stain the tooth structure, and finally the action of sulfids in the 



BLEACHING METHODS FOR SPECIAL STAINS 543 

structure of a pulpless tooth may react with amalgam fillings, forming 
salts of mercury, silver, tin, copper, etc., which are absorbed by the 
tooth, resulting in its discoloration. The treatment of these stains, 
which were grouped as Class III at the beginning of this chapter, 
is extremely difficult and often unsatisfactory. However, there may 
arise individual cases of discolorations of this class in which it is of the 
utmost importance to remove them, and much may often be accom- 
plished when the causes of the discoloration are known and the proper 
bleaching method is applied. 

Gold stains may arise, as has been already indicated, from the inju- 
dicious use of gold instruments or failure to remove all gold fillings 
when applying some one of the chlorin methods of bleaching. In the 
course of time when this has happened the tooth assumes a pinkish 
hue, which merges into a characteristic violet or purple, finally becoming 
black. 

Iron stains may arise from the use of steel instruments in connection 
with the chlorin methods of bleaching or in contact with iodin or any 
of the mineral acids in connection with canal treatment. The iron stain 
is yellowish at first, gradually becoming brown and finally black. 

Copper and nickel stains may arise from contact with these metals 
or their alloys, as copper amalgam or nickel or German silver dowels 
for artificial crowns or anchorages for fillings. The stains from these 
metals are — for copper, bluish to black, and for nickel, a characteristic 
chlorophyl green, which eventually becomes black. 

The best general treatment for all of the foregoing stains is to 
bleach the tooth by the chlorin method, with special care as to the 
several precautions already recommended; and when the color of the 
metallic stain has been discharged by conversion of the dark-colored 
salt into a soluble chlorid, wash the tooth thoroughly first with dilute 
chlorin water, 50 per cent., and afterward with hot distilled water, to 
remove all of the metallic chlorid which has been formed. The process 
may require repetition to secure permanent results. 

Silver stains are comparatively easy to remove, either by an appli- 
cation of the chlorin method or by saturating the tooth with tincture of 
iodin, thus converting the silver salt into a chlorid or iodid, as the case 
may be, after which it may be dissolved out with a saturated solution 
of sodium hyposulfite applied as a bath to the tooth. For this pur- 
pose the Hollingsworth bulb dam (see Fig. 569) answers admirably, 
and although the experiment has not as yet been tried, there is good 
reason to believe that the cataphoric method with electrodes applied in 
reverse order would under these circumstances greatly facilitate the 
solution and removal of the metallic salts. 

Mercurial stains are always black from the formation of mercuric 
sulfid, and are removable by the same method as are silver stains, with 
the exception that when the stain has been converted into a chlorid 



544 DISCOLORED TEETH AND THEIR TREATMENT 

by the chlorin method, the mercuric chlorid is best removed by an 
aqueous ammoniacal solution of hydrogen dioxid, or when the stain 
has been converted into mercuric iodid by the use of a saturated solu- 
tion of potassium iodid. In both cases a final washing with hot dis- 
tilled water is a sine qua non. 

Manganese stains frequently occur from the use of potassium per- 
manganate, in solution or in substance, in the treatment of putrescent 
canal conditions. The manganese stain is a characteristic mahogany 
brown. It is very readily removed by a 25 per cent, aqueous solution 
of hydrogen dioxid in which oxalic acid crystals have been dissolved to 
saturation. A few applications of this mixture will quickly decolorize 
the stain, after which a liberal treatment of hot distilled water is 
required as in the foregoing cases. 

In all cases a careful diagnosis of the chemical nature of the dis- 
coloration should be made when possible. Much information upon this 
point may be gained by a detailed study of the present condition of the 
tooth and its environment, but in addition to this the patient should be 
questioned as to the history of the case, and especially as to its previous 
treatment. The data thus obtained should be carefully noted, and treat- 
ment instituted in accordance with the conditions to be met. 

Success in the bleaching of teeth demands a recognition of the fact 
that each case presents individual peculiarities, that the problem is 
essentially a chemical one always, and that the bleaching method in any 
given case must be selected with special reference to the character of 
the discoloration and applied with due care as to its details in order that 
the chemical requirements of the operation may be intelligently met; 
without which care success is impossible. 



CHAPTEE XVII 
EXTRACTION OF TEETH 

By M. H. CRYER, M.D., D.D.S. 
INDICATIONS FOR THE OPERATION 

It is impossible to formulate a set of exact rules by which the prac- 
titioner may be governed in deciding upon the extraction of teeth. So 
many circumstances, both local and general, must be taken into consid- 
eration that little more can be done than to suggest the most important 
causes which demand the operation. 

Deciduous Teeth. — The indications for extracting deciduous teeth 
are — 

First: When the teeth are a source of irritation affecting the general 
health or comfort of the child and do not respond to treatment. 

Second: When the deciduous teeth are preventing the eruption of 
the permanent teeth into their normal positions. Occasionally a de- 
ciduous tooth will assist in the proper placing of a permanent one, 
in which case it should not be removed as long as it is of such use. 

Third: When a lower permanent incisor shows signs of erupting on 
the labial side of the deciduous tooth the latter should be removed at 
once, but if the erupting tooth appears on the lingual side the removal 
of the deciduous tooth may in that case be delayed somewhat longer. 

Fourth: When upper permanent incisors show a tendency to erupt 
on the palatal side of the temporary teeth the latter should be extracted, 
but when they are erupting on the labial side the deciduous teeth may 
be allowed to remain for a time, as they are often useful in forcing the 
permanent teeth outwardly. This, however, must be closely watched 
to prevent the permanent incisors from moving too far. 

Permanent Teeth. — The indications for extraction of the permanent 
teeth are — 

First: Diseased roots which cannot be cured and so made useful 
for crowning, or assisting in retaining a bridge, plate, or other pros- 
thetic device. 

Second: Teeth of mastication that have lost their occluding teeth 
and in consequence thereof are being pushed from their alveoli and are 
a source of trouble. x\s a rule, this refers only to the second or third 
molars, and more particularly to the third molar. When it occurs with 
other teeth the opposite vacant space should be filled by an artificial 
tooth to prevent the extrusion of the natural tooth. 

35 (545) 



546 EXTRACTION OF TEETH 

Third: When incurable abscesses originating from teeth in the upper 
jaw tend to open into the nasal chamber, maxillary sinus, or zygomatic 
fossa the teeth associated with such abscesses should be extracted. 
When diseased teeth are the exciting cause of an incurable abscess in 
the lower jaw which opens or threatens to open externally on the chin, 
jaw, or below the bone into or upon the neck, they should be removed. 

Fourth: Teeth which occupy irregular positions in the arch, that 
cannot be corrected so as to become useful or contribute to the general 
symmetry of the mouth, should be removed. 

Fifth: Erupting teeth that are retarded because of lack of room 
in the jaw, if giving pain, or are causing reflex disturbances, should be 
extracted or else the tooth that is preventing the eruption should be 
removed. A marked example of this is often found in the eruption of 
the third molar when all the other teeth are of good size and are in 
place. These molars when retarded often cause the greatest distress, 
sometimes producing serious results, and must then be extracted; if they 
cannot be safely removed the second molar may be extracted, in conse- 
quence of which the third molar will usually be erupted near its place. 
When an upper third molar is erupting under the same circumstances 
there is usually less difficulty, as, having but slight resistance distally, 
it can erupt outwardly or slightly backward, though should it impinge 
upon the soft tissues covering the ramus of the lower jaw it should be 
extracted. 

Sixth: Teeth so badly diseased that they will not respond to treat- 
ment and are a source of discomfort to the patient should be removed, 
as they impair the general health. 

Seventh: First molars. There has been much discussion regarding 
the early extraction of these teeth, many claiming that if the pulp of 
one becomes devitalized at an early period of life and it is deemed best 
to extract it, the other three should also be removed. No fixed general 
rule, however, can be given; each case must be considered separately. 
There are cases where the extraction of all is necessary, and others 
where it would be a most unwise thing to do. When the anterior teeth 
are fully in position, the bicuspids occluding correctly and the second 
molars are about to erupt, the case may then be one for extracting the 
four first molars, provided it be necessary to extract one of them, or 
if it be likely that one or more of them will be lost in a few years. If, 
however, the bicuspids are not in good position, it is better not to extract 
the first molars, as they assist in keeping the jaws the proper distance 
apart, and in preventing the lower anterior teeth from biting against 
the upper gum. 

Removal of Sound Teeth Preparatory to Inserting Artificial Dentures. — 
When preparing the mouth for an artificial denture the removal of sound 
teeth may be indicated as a measure of expediency in relation to mechan- 
ical and hygienic considerations. For example; 



INDICATIONS FOR THE OPERATION 547 

1. Roots which a plate or bridge would cover, excepting when they 
assist in holding the device. 

2. Teeth from which the gums have receded to such an extent as 
to become useless or unsightly. 

3. Teeth that are being extruded from their alveoli from the ab- 
sence of occluding teeth. The extraction of these depends, however, 
on the extent of "elevation" and the possibility of placing occluding 
artificial teeth in position. 

4. Where there is but one tooth remaining, or two teeth standing 
together, or in certain cases when several isolated teeth remain which 
cannot be made to contribute to the mechanical adaptation of an arti- 
ficial denture, extract when in the upper jaw. They interfere with the 
fitting of an upper plate, but in the lower jaw they may be useful in 
retaining the plate. 

5. When there are two teeth, one on each side of the upper jaw, in 
good position and of desirable shape for clasping, do not extract unless 
they are the third molars or the oral teeth. 

6. In preparing the upper jaw when two canine teeth alone remain, 
or when there is also a molar or bicuspid, or both, and it is decided to 
extract the molars and bicuspids, then extract the two canine teeth also. 
It has been claimed by some of the very best dental practitioners, whose 
opinions must be respected, that by keeping these teeth the expression 
of the face is less likely to be marred. For the following combined 
reasons, however, extraction is advised: 

(a) It is very difficult to obtain a correct impression of the mouth 
while these teeth only are in position. 

(6) It is nearly impossible to perfectly match, grind, and arrange the 
lateral incisors beside single canines. 

(c) The adhesion of the plate to the mouth is interfered with, as air 
and food work in between the plate and these natural teeth. 

(r/) The plate is very much weakened by being cut out for the accom- 
modation of these teeth at what might be termed the abutments of the 
arch. 

In the lower jaw single teeth which are sound are usually of great 
importance. They should not be removed, as they assist in retaining 
a denture by means of clasps or other devices. Especially is this true 
in persons advanced in years, as then the alveolar process is generally 
much absorbed. If the lower process is much absorbed, even an imper- 
fect tooth will do good service of this character for a time; and if it is the 
first plate the patient has worn it will serve a good purpose by assisting 
in the retention of the plate until the patient has become accustomed 
to it, after which the tooth, if giving trouble, or if it is unsightly, may 
be removed and an artificial one placed on the plate. 



548 



EXTRACTION OF TEETH 



Fio. 573 




INSTRUMENTS AND ACCESSO- 
RIES FOR EXTRACTING 

The instruments used in ex- 
tracting teeth are forceps and 
elevators of various shapes and 
sizes. 

Forceps. — The forceps should 
be made of steel of the best qual- 
ity for the purpose obtainable, in 
order to give great strength and 
stiffness and at the same time 
toughness, so that they will not 
break. Forceps that will spring 
or bend destroy the sensitivity of 
the hand using them in such a 
way as to prevent the operator 
from discerning in what direc- 
tion the resistance to extraction 
is being made. The beaks of the 
forceps as a general principle 

Fig. 574 




Antiseptic universal lower molar forceps. 



Joint of an antiseptic lower molar forceps. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING 549 



Fig. 575 



should be shaped so as to fit and adjust themselves to as great a surface 
of the various teeth or roots as possible, so that they may take a firm 
hold. They should be at such an 
angle in relation to the handles 
as will permit them to be easily 
and readily placed in the proper 
position without obscuring the 
view of the tooth to be extracted. 
The inner surface of each beak 
should be concave in a transverse 
section and without serrations, as 
these are of no assistance, but 
tend to weaken the beaks and are 
difficult to clean. The edges of 
the concave portion should be 
sharp enough to cut through the 
alveolar process if necessary. 
The points of the beaks should 
be sharp and tapering so they can 
be forced into position. The 
handles should be of a shape to 
allow a firm grasp, and as the 
hands of different operators vary 
in shape and size it will be evi- 
dent that the same size of forceps 
handles will not be perfectly sat- 
isfactory to all. The curvature 
of the handles should vary ac- 
cording to the general or special 
use of the forceps. The curved 
ends, as seen in Fig. 573, are of 
little use, and should be done 
away with in all forceps excepting 
perhaps those made especially for 
the upper and lower molars. 

The joints of extracting instru- 
ments should be so made that 
the handles can be separated by 
some simple mechanism to permit 
of thorough and easy cleansing. 
Figs. 573 and 574 represent an 
instrument of this character. 
There are others of the same 
nature, but this being the most 

Simple and the Strongest Should Knuckle-joint root forceps. 




550 EXTRACTION OF TEETH 

be generally adopted unless a similar device can be adapted to the 
"knuckle-jointed" instrument (Fig. 575). 

There should be no sharp angles or crevices, and if the ordinary 
forceps be used, that portion around the joint in a transverse section 
should be oval. Forceps are often made with octagonal joints, but these 
should be condemned, as they may not only hurt the lips of the patient, 
but in case of a slip, which may happen with the best operators, they 
are more liable to cause injury by striking the other teeth; moreover, 
they are very clumsy and require more room. 

Unless the antiseptic joint (Figs. 573 and 574) is used the union of 
the joints is usually made upon one of two principles: First, by one-half 
passing into a mortise in the other and held in the centre by a pinion 
(Fig. 576). The second is known as a knuckle-joint (Fig. 575) made 
by each portion being let half-way into the other and held together 
by a screw. This is a neater joint and does away with many of the 
objectional features noted in other forms of forceps joint. 

All handles should be serrated, as shown in the illustrations, and the 
instruments if properly cared for need not be nickel-plated. The 
number of forceps in a practical set will vary with the requirements of 
every individual who extracts teeth, therefore only the general principles 
which should govern the selection of a set of instruments will be here 
given; at the same time the uselessness of a very large selection is here 
emphasized. As an illustration of the range of tooth extractions which 
may be performed with a limited number of instruments, the forceps 
represented by Figs. 576 and 577, showing the exact size, will serve as 
examples. They are smaller than the ones generally used, especially in 
America. 

The instruments shown in Fig. 576 may be used almost universally for 
the upper teeth. 

Fig. 577 is a forceps of the same general character as that in Fig. 
576, only the beaks are at a different angle with the handles. This pair 
may be used similarly for the lower teeth. These forceps are useful in 
all cases, except in the full arch, when either a first or second molar is 
to be extracted. If the teeth are large, the jaw strong, and the line of 
grinding surfaces concave, it is better to use the special lower molar 
forceps as shown in Figs. 573 and 586. 

Figs. 578 and 579 represent very useful forceps for extracting the 
ten upper anterior teeth. Fig. 579 has longer beaks and its points are 
finer. In skilful hands where too great a force will not be brought to 
bear on the points they are the better forceps. Under nitrous oxid 
and where many teeth are to be extracted, thus requiring rapid work, the 
instrument shown in Fig. 578 is preferable. 

Figs. 580 and 581, right and left, represent forceps specially used for 
extracting the first and second upper molars on either side. The outer 
beak is made pointed for the purpose of passing in between the buccal 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING 551 

roots, the inner beak is concave in order to grasp the palatal root. Figs. 
583 and 584 show bayonet-shaped forceps, that illustrated by Fig. 583 



Fig. 576 



Fig. 577 



f 

<> Seas 

M 
W 



Universal upper incisor and root forceps. 



Universal lower incisor and root forceps. 



being specially made for extracting the upper third molars, Fig. 584 
being used for upper roots. The ends of the handles of all forceps which 



552 



EXTRACTION OF TEETH 



Fig. 571 




Fig. 579 



I.::/,; 



m 



For the ten upper anterior teeth. 



Root, upper front (straight). 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING 553 



are forced in by the palm of the hand should have a broad surface, as 
shown in Fig. 584. These forceps are popular with many operators. 
The writer considers them 

Fig. 580 

clumsy, as they obscure the 
proper view of the tooth and 
its associated parts. 

Forceps for Extracting Lower 
Teeth. — Instead of the beaks 
of the forceps being nearly on 
a line with the handles, as in 
those for the upper jaw, they 
are bent at nearly a right angle. 
For the incisors of the lower 
jaw there are no better forceps 
than those shown in Fig. 577. 
This instrument is very useful 
in extracting the lower third 
molar when fixation of the jaw 
from diffuse cellulitis in the 
region of the temporomaxillary 
articulation renders it difficult 
to open the mouth sufficiently 
for inserting a larger instru- 
ment. In such cases the for- 
ceps should be carried back- 
ward in the vestibule of the 
mouth with the inner beak 
passing between the upper and 
lower teeth; when the beaks 
reach the third molar the in- 
ner beak can usually be forced 
over the inner surface of the 
tooth and into position, after 
which the tooth can be grasped 
and extracted. The forceps 
represented in Fig. 576 can 
also be used to advantage for 
these teeth, the operator stand- 
ing behind and working over 
the head of the patient, as 
shown in Fig. 639. 

Fig. 582 exhibits a hawk- 
beaked forceps for extracting 
the anterior lower teeth. It is 
very popular with some oper- 




554 



EXTRACTION OF TEETH 



ators, especially those in Europe. The writer does not recommend it. 
Ficr. 585 also exhibits a special instrument. It is made for extracting 



Fig. 581 



Fig. 582 




Left upper molar. 



Hawk-beaked forceps. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING 555 

Fig. 584 



Fig. 583 




ve 



mm 



1 



i 



Universal upper third molar. 



Dorr's upper root forceps. 



556 



EXTRACTION OF TEETH 



the lower canine and bicuspid teeth of either side. Fig. 586 is a 
special instrument used for the lower molars of either side. The beaks 



Fro. 585 



Fig. 586 




Universal lower canines and bicuspids. 



Universal lower molars, designed by 
Dr. Chapin A. Harris. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING 557 



Fig. 587 



Fig. 588 



Fig. 589 




Root, lower. Half curved. 



Elevator. 



Right and left scalers used 
for extracting roots. 



558 



EXTRACTION OF TEETH 



are pointed, with a concavity on each side of the point to allow it to pass 
in between the roots. The two concave portions fit against each root. 



Fig. 590 



Fig. 591 




Lancets with ebony handles and with solid steel handles. 



Figs, 
mode of 



Fig. 587 represents a universal lower root forceps which 
is preferred by many to that shown by Fig. 585. 

Elevators or Root Extractors. — There are many kinds of 
elevators used in extracting roots. Some are also occasion- 
ally used in the extraction of teeth (usually the third 
molar). 

Fig. 588 shows one of the most useful forms of this instru- 
ment. It is especially useful in extracting third molars when 
the teeth in front of them are in position. Also for the 
removal of impacted teeth by passing in between the impacted 
tooth and an adjoining tooth, or between the tooth and the 
bone, the concave portion being placed against the tooth to be 
removed. It is also useful as a gouge at times in removing 
bone that is overlying an impacted tooth. 

Fig. 589 represents two elevators; they are similar to right 
and left scalers, being made somewhat heavier; they are 
extremely useful in extracting roots. They are so unlike 
an extracting instrument that patients do not dread the ap- 
pearance of them as they do that of forceps. By carefully 
inserting the blade with the point toward the root to be 
removed, between it and the adjoining root or tooth, and 
giving a slight rotary motion, the point will force the root 
from its socket with but little pain. 
630 and 631 illustrate two other forms of elevator, with their 
application in the removal of roots. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING 559 



Fig. 592 



Lancets. — Figs. 590 and 591 represent various forms of lancets, 
the more useful of which are Nos. 1 and 5, which are all that are required 
for lancing in extracting or for relief of retarded eruption of deciduous 
or other teeth. They are also useful in general surgery of the mouth. 
The handles should be made of metal instead of wood, in order that 
they may be thoroughly sterilized. 

Scissors. — A good pair of curved 
scissors, as shown in Fig. 592, should 
be at hand in case a portion of gum 
tissue is found to be attached to the 
root. If the scissors were slightly more 
curved they would be even better 
adapted for this purpose. 

In connection with the instruments 
already mentioned, there should be 
a mouth mirror (Fig. 593) and a few 
45 degree angle hatchet-shaped exca- 
vators and probes for general exami- 
nation of the teeth, especially for 
examining the position and character 
of a root or impacted tooth which it 
is purposed to extract. 

Fig. 593 





Curved scissors. 



Mouth mirror. 



Mouth Props. — When an anesthetic is to be given it is advisable to 
use some kind of a mouth prop, in order to keep the mouth well open. 
Corks lh inches in length, lj inches at the base, and f of an inch at the 
small end are very useful for this purpose when placed between the 
jaws, with the small end in the mouth. Some operators do not use 
them, as they may interfere with the giving of the anesthetic by impeding 
respiration upon beginning the administration. The majority of patients, 



560 



EXTRACTION OF TEETH 



if asked to hold the mouth open while taking the anesthetic, especially 
nitrous oxid and oxygen, will keep it open during the anesthetic stage. 

Fig. 594 illustrates excellent props devised by Dr. Frederic Hewitt, 
of London, England. 



Fig. 594 




^c^ 




Hewitt's mouth props (half size). 
Fig. 595 




Mechanical mouth-opener (half size). 
Fig. 596 




Pharyngeal forceps (half size). 

The Mechanical Mouth-opener (Fig. 595). — This instrument is made 
in various shapes and sizes. It is inserted between the jaws when the 
props are to be removed or in cases of trismus, and may also be used 
to separate the jaws and retain them so in cases of emergency or during 
certain operations within the oral cavity. 

All dentists, and especially those who extract teeth, should have at 
least one pair of pharyngeal forceps (Fig. 596). It is possible that they 
may never be used, but on the other hand an accident may occur such as 



SURGICAL ANATOMY 



561 



a fragment or tooth slipping into the pharynx, where if the finger cannot 
reach it this instrument will be absolutely necessary. 

Surgical Anatomy. — To extract teeth successfully it is first necessary to 
be perfectly familar with the general shapes of the different teeth and 
their position in relation to the jaw and to their associates, in order 
that the operator may intelligently apply the force in the line of the 
least resistance required for their removal. This knowledge cannot 
be obtained from books; they are but the guides to it. The jaws of the 
dead subject must be dissected — both the cleaned bones and those with 
the soft tissues left upon them. "Dissection" means that not only 
shall the superficial relations be studied, but that the bones shall be cut 
in various directions, both with the saw and other instruments, until 
the relations of the teeth of the upper jaw with the floor of the nasal 
chamber and the maxillary sinus are fully understood. In the lower 
jaw the relations of the teeth with the inferior dental canal and the 
position of the roots, especially those of the third molar, must also be 
thoroughly known. 

Fig. 597 




Alveoli of permanent teeth (upper jaw). 



The alveolar process of both jaws is made up of two plates, external 
and internal, consisting of dense compact bone without a true line of 
demarcation between the process and maxilla proper. The sockets for 
the roots of the teeth are situated in the interspaces between these plates 
and are surrounded by a very thin porous plate of cortical bone. The 
remaining space is filled with cancellated tissue, small bony channels, 
36 



562 



EXTRACTION OF TEETH 



connective tissue, nerves, vessels, etc. As this process belongs to the teeth, 
is developed with them, and is for the purpose of holding them in posi- 
tion, it disappears to a greater or less extent when the teeth are lost. The 
resorption of this process does not take place alike in each jaw. In the 
upper jaw the external plate disappears more rapidly and to a greater 
degree than the inner plate; in the lower jaw the resorption of the two 
plates is about equal in extent and rate. The inner plate of the upper jaw 
is partially supported by the external plate of the palatal process ; in fact, 
one merges into the other. The outer alveolar plate of the upper jaw 
being resorbed to a greater extent than the inner one is of advantage 

Fig. 598 




Alveoli of permanent teeth (lower jaw). 



to the dentist in fitting teeth to the gums; consequently, in extraction 
that fact should be remembered and injury to the internal plate avoided. 
At the same time it does no harm to remove a small portion of the outer 
plate, though loss of the gum tissue should be avoided if possible. In 
the lower jaw it is not so important to avoid removing slight portions 
of the inner plate, as resorption takes place about equally in the two 
plates. 

These plates may be resorbed in such a manner that a slight ridge 
is left between the places which they occupied. This resorption pf 



SURGICAL ANATOMY 



563 



both plates of the alveolar process of the lower jaw makes it more diffi- 
cult to fit single plain teeth in the lower than in the upper jaw. 



Fig. 599 




Typical upper and lower jaw. 
Fig. 600 




Showing the occlusal surfaces of the upper teeth. (From same skull as Fig. 599.) 

Fig. 597 shows the alveoli of the upper denture, Fig. 598 that of the 
lower. 



564 



EXTRACTION OF TEETH 



Fig. 601 





Showing occlusal surfaces of the lower teeth. (From same skull as Fig. 599.) 

Fig. 602 







Showing the buccal surfaces of the crowns and roots in position. 






SURGICAL ANATOMY 



565 



Fig. 599 illustrates a typical upper and lower jaw, the external sur- 
faces of the crowns of the teeth, also a normal occlusion. Figs. 600 
and 601 illustrate the occluding surfaces of the teeth and their relations 
with each other. They are made from the same skull as Fig. 599. 

Fig. 602 is from a photograph taken from the right side of a skull. 
It gives a good representation of a fairly normal occlusion of the teeth, 
their shape, roots, and their relation with the cancellated tissue and 
the inferior dental canal or cribriform tube of the lower maxilla. In 
the upper jaw the bone is thin over the position of the molar teeth, and 
their roots are comparatively straight; none of these should be difficult 
to extract. The buccal roots of the first molar are somewhat divergent 
from each other. The same roots of the second molar spread only 
slightly, as they leave the crown and close in at the points. The roots 

Fig. 603 




From the same jaw as Fig. 60S 



of the third molar are together and slightly curved backward. In 
the lower jaw the roots are comparatively straight. Those of the first 
molar are spread only a little apart, this being the usual condition. 
The roots of the second molar are almost straight and are nearly parallel 
with each other. The anterior root of the third molar curves slightly 
backward until it joins the posterior root. 

Fig. 603 is taken from the left side of the same jaw as Fig. 602. In 
Fig. 602 the roots have been exposed down to their apices; in Fig. 603 
only the external or cortical plate has been removed. These two illus- 
trations give a correct idea of the relations of the teeth to the internal 
structures of the jaw. 

Figs. 604 and 605 are good illustrations of the relations of the roots 
with the floor of the maxillary sinus usually found in the white race. 



566 



EXTRACTION OF TEETH 



In the negro there is usually a considerable thickness between the 
teeth and the floor of the sinus. It will be noticed that the roots of 
the molars pass up on both sides of the sinus, and because of this fact 
it is necessary in extracting teeth from a jaw of this character to use 
the greatest caution, otherwise a portion of the floor of that cavity might 
also be removed. Or if a tooth be broken and much upward force used 



Hiatus 
semiluminari. 



Fig. 604 

Middle ethmoidal 

cells. 




Crystalline lenses. 



Uncinate process. 
Middle turbinated 

bone. 
Middle meatus. 
Maxillary sinus, 
nferior meatus. 
Inferior turbinated bone 



-Vestibule of mouth. 
First molar. 

Distal root first molar. 
Inferior dental nerve. 



An anterior view of a vertical transverse section of the head, showing the relations of the jaws and 
the U-shaped bone of the mandible. 



in endeavoring to take hold of the root, the latter could easily be forced 
into the sinus. The lower portion of Fig. 604 gives a general idea of 
a transverse section of the lower jaw made posterior to the mental 
foramen. Special attention is drawn to the U-shaped formation of 
the cortical portion of the lower jaw which terminates in the two plates 
of the alveolar process, and between which the roots are embedded in 
the cancellated tissue. It also shows how the roots extend toward the 



SURGICAL ANATOMY 



567 



inferior dental nerve. There is no line of demarcation between the 
alveolar process and the body of the bone. 



Oms 




Oms 



1st M 1st M 

Posterior view of vertical transverse section of the head from the same skull as Fig. 604, showing 
the ostium maxillare, which is indicated on each side by a cord passing through it: Om, ostium 
maxillare; 1st M, first molar. 

Fig. 606 shows the relation, length, and position of the second bicus- 
pid, showing that its root is sometimes placed to the inner side of the 
anterior root of the first molar. The roots of these bicuspids are flat, as 

Fig. 606 




Ar 1st M, anterior root of first molar; R 2d Bi, root of second bicuspid; Idn, inferior dental 
nerve; Lip, U-shaped or cortical section of lower jaw. 



will be seen by looking at Fig. 626. On taking into consideration their 
length, position, and thinness it will be readily seen why it is so often 
difficult to extract them without breaking. 



568 



EXTRACTION OF TEETH 



Fig. 607 is taken from horizontal sections of the lower and upper 
jaws, showing the transverse sections of the roots of the teeth. The 
section is made a little above the margin of the alveolar process of the 
upper jaw and a little below in the lower. The illustration shows the 









V: ^^ 



Fig. 607 

Central Lateral 

incisor, incisor. Canine. 



l-V 



*!%>**■ 



I i 



fa T 



**§mr% 



First bicuspid. 
Second bicuspid. 




""■-Second bicuspid. 
First bicuspid. 



Horizontal section of the upper and lower jaws cut a little beyond the free margin of the alveolar 
process, showing the forms and position of the roots of the various teeth. 






shape and position of the various roots, with their relations to the pro- 
cess and to each other. Particular attention should be given to the fact 
that the roots and process are in such close relation as to make it im- 
possible to force the beak of a forceps between them without breaking 
one or both plates of the process. The lines leading from the roots 



SURGICAL ANATOMY 



569 



show the proper direction for applying what is known in extracting 
as the "out-and-in motion." 

Fig. 608 represents a horizontal section made through the lower jaw 
near the ends of the roots, and from the same bone as that shown in the 
lower half of Fig. 607. The cancellated portion with the soft tissue 
filling the spaces can be plainly seen. The nerve passing into its tube, 
the ends of the roots of the second and third molars, the tip of one of 
the roots of the first molar, and the roots of the first and second bicus- 
pids are all plainly shown. A little of the lateral incisor can be noticed, 
but the centrals do not reach so far down. 



Fig. 608 




SM** 




Horizontal section of the lower jaw cut in the region of the points of the roots of the teeth: 
DN, dental nerve; R 3d M, roots of third molar; R 2d M, roots of second molar; R 1st M, distal 
root of first molar; R 2d Bi, root of second bicuspid; R 1st Bi, root of first bicuspid; Re, root of 
canine; RH. root of right lateral incisor. 



Figs. 609 and 610 are taken from a sagittal section of the upper 
jaw, external to the infraorbital foramen, and through the roots of the 
molar teeth. This illustration shows how the roots often extend above 
the lower portions of the floor of the sinus, an abscess from the palatal 
root of the first molar having discharged into the floor of the sinus 
at the point Aa. 

It has been demonstrated both anatomically and clinically that in- 
fectious matter from a suppurating tooth may eventually give rise to an 
inflammation of the meninges of the brain. Should pus form a dento- 



570 



EXTRACTION OF TEETH 



Fig. 609 



Fig. 610 





Anteroposterior division of the maxilla, showing 
opening of a dental abscess within the antrum and 
an infraorbital sinus: Ifs, infraorbital sinus; //, in- 
fraorbital foramen; Pic, piece of paper passing 
through infraorbital canal; Ms, maxillary sinus; 
Ac. apical abscess. 



Fig. 611 



Om, opening into malar bone; Ifs, 
infraorbital sinus. 




Longitudinal division of a mandible, exposing the cancellated tissue in the body of the jaw and 

between the sockets of the teeth. 



SURGICAL ANATOMY 



571 



alveolar abscess discharge into the maxillary sinus it may pass out into 
the hiatus semilunaris and ascend into the frontal sinus or in the vicinity 
of the cribriform plate of the ethmoid through the infundibulum when 
the passage through the hiatus into the middle meatus is small or con- 
stricted, as it usually is when inflamed, or the pus may pass directly 
through the infundibulum. Recent research has shown that the frontal 
sinus, the cribriform plate of the ethmoid, and the meninges of the brain 
are in close relation at the anterior portion of the cribriform plate, a dis- 
eased condition at which point is liable to involve all three structures. 



^ r~ 




Fig. 612 
SI 













F G H I J 

Sections made at different points from a mandible which was not quite normal in its density. 

Fig. 611 is from a longitudinal section of the lower jaw, and gives a 
good idea of the cancellated tissue, the relations of the sockets of the 
teeth to one another, and the position of the inferior dental canal. 

Fig. 612 is taken from several transverse sections of a lower jaw 
The bone is not quite normal, as several teeth were extracted before 
death, the loss having caused changes in the character of the bone. 
Some of the sections show but one canal, while in others there are many, 
requiring close observation to determine in which the inferior dental 
nerve and vessel have passed. 

Fig. 613 is taken from the inner side of the right half of a lower jaw. 
The second molar has been broken off, the roots still remaining in 
position. The points of the roots of the third molar pass out through 



572 



EXTRACTION OF TEETH 

Fig. 613 






Fig. 614 



£.*^ 




1: 




An uncommon impacted lower third molar. 



dl 



Fig. 615 




A view of an impacted lower third molar. 



SURGICAL ANATOMY 



57; 



the inner wall a considerable distance below the mylohyoid ridge. A 
portion of the ridge has been cut away, exposing the remainder of the 
internal surface of the roots. This will be further alluded to when 
extraction of the lower third molar is considered. 



Fig. 616 




A second view of an impacted lower third molar, as shown in Fie. 615. Part of the distal root of 
the second molar has been resorhed, exposing the root canal, more than likely causing the devitali- 
zation of the pulp, and thus producing neuralgia. 

Fig. 617 




Inner side of left half of lower jaw, showing an impacted third molar. 

Figs. 615 and 616 are from the outer side of "the right half of a lower 
jaw, Fig. 615 showing an impacted- third .molar lying horizontally in 



574 



EXTRACTION OF TEETH 



the jaw. Fig. 616 is of the same jaw with the tooth removed from its 
bed, showing the inner surface. The second molar is a pulpless tooth 
the distal root of which shows where the impacted tooth has pressed 



Fig. 618 







Same as Fig. 617, with the impacted molar removed from his bed. 



against it, causing the absorption of a portion of the root and exposing 
the pulp canal within, producing death of that organ. This must have 



Fig. 619 




Right half of lower jaw, showing a lower third molar with thickened and curved roots. 



caused neuralgia. The cancellated tissue of this bone, it will be noticed, 
is not like that shown in Fig. 603, the change in the character of this 
tissue being the result of irritation. It will be seen that the roots of the 



SURGICAL ANATOMY 



575 



other teeth in this jaw are longer than usual, the canine tooth passing 
below the nerve and to the outer side. 



Fig. 620 




Left half of lower jaw, showing a third molar lying horizontally and the bone much more 

dense than normal. 

Figs. 617 and 618 represent the inner side of the left half of a lower 
jaw. It shows an impacted third molar pointing slightly downward. 
The distal root of the second molar is slightly absorbed. On uncover- 

Fig. 621 




Showing two ordinary impacted lower third molars. 



ing the tooth and taking it from its bed, it was found to be incased in a 
thin shell of bone, as though the dental sac had ossified separately around 
this tooth; this thin incasement of bone may, however ; have been an 



576 



EXTRACTION OF TEETH 



inflammatory product. The inner portion of this shell can be seen in 
position. The nerve and its accompanying tissue passes into the infe- 
rior dental foramen immediately against the shell, and has the appear- 
ance of being flattened out. It divides and sends a branch around the 
internal half of the shell. 

Figs. 619 and 620 are taken from the right and left halves of the 
lower jaw. Fig. 619 shows the internal surface of the right half; Fig. 
620 the external surface of the same. In Fig. 619 the roots of the 
third molar curve backward, are joined together, and are so enlarged 

Fig 622 



I 






■L 




w~s 






L Ijjjli 1 


\\ 




|^^ 





x-ray picture made from the left side of Fig. 621. 

by an abnormal deposit of cementum, caused by continued hyperemia 
due to the prolonged irritation that the form of each root is lost; the 
bone also is much thickened. Fig. 620 shows an impacted tooth press- 
ing directly against the one in front of it, the roots of which have become 
much enlarged by the deposit of cementum. The surrounding bone 
is also thickened and much more compact than the normal bone. The 
character of the cancellated tissue of the lower jaw is lost by the deposit 
of bone caused by continued irritation of that tissue. 

Figs. 625 and 626 show the normal forms of the teeth, and Fig. 627 



SURGICAL ANATOMY 



577 



is taken from a group of abnormal teeth. If only normal conditions 
of the teeth had to be considered, as shown in Figs. 625 and 626, extrac- 



Pm 




Fig. 623 






Side view of two ordinary impacted lower third molars, the bone having been removed in order 

. to expose the roots. 



Fig. 624 




Showing an inverted lower third molar erupting into the submaxillary fossa, (Dr Ottofy ) 

37 



578 



EXTRACTION OF TEETH 



tion would be a very simple operation, but unfortunately this is seldom 
the case. It often happens that even when the teeth themselves are 
normal they are situated in abnormal positions, and for this reason 
alone their extraction becomes necessary. In fact, so varied and com- 



Fig. 025 




Deciduous teeth — left side. (Burchard.) 



plicated are the different abnormalities presented, that it would be 
impossible to describe them all. The diagnosis of unerupted teeth occu- 
pying abnormal positions has been greatly facilitated by special applica- 
tions of the skiagraphic method. Its further use in this connection is 
but a question of time and development. A careful study of the com- 



Fig. 626 




Permanent teeth — right side. (Burchard.) 



plications most frequently occurring will, however, give good preparation 
for meeting the emergencies. 

Figs. 613 to 624 and 628 show abnormal positions of various teeth. 
It will be readily seen that no set of rules could be made to govern the 



GENERAL PRINCIPLES 



579 



extraction of these teeth; therefore only the general principles govern- 
ing extraction can be here set forth. 



Fig. 627 








Abnormalities in teeth. 



GENERAL PRINCIPLES IN EXTRACTING TEETH 

These principles may be classified under the following heads: 

1. Management and Position of Patients* 

2. Selection of Instruments. 

3. Technique of the Operation, 



580 EXTRACTION OF TEETH 

Managemant of Patients. — The first important step toward a suc- 
cessful operation in dentistry is to gain the confidence of the patient, 
who must be brought to rely entirely on the judgment and skill of the 
operator. If the operator feels entire confidence in his own ability to 
carry out successfully an operation, he can, by his manner of approaching 
the patient, impart a feeling of almost absolute trust in his skill. This 
feeling of confidence in himself should be cultivated, as it is evident 
that a slight nervousness on his part, even though he be most skilful, 
will tend to alarm the patient to such an extent as may cause great 
interference with the operation. 

Fig, 628 




(4 
Abnormal jaw showing impacted canines. 

Position of the Patient.— The principal object to secure in 
placing the patient is to obtain a good view of the affected tooth and 
contiguous parts; after which the position should be made as comfort- 
able as possible both for the patient and operator, taking care that the 
territory of operation can be reached with but little strain or effort. 

The position both of patient and operator varies slightly for the 
extraction of each tooth. The main points to be observed are to have 
the particular tooth to be operated upon in view, and the head of the 
patient in such a position that it can be controlled by the left arm and 
hand. 

The chair should be steady, strong, and comfortable, with arms and 
a good head-rest of rather a concave shape. It should also have a suit- 
able foot-rest. (For further description of chair for anesthesia see page 
613.) When the regular dental chair is not obtainable, an ordinary 
strong wooden chair can be used. If two of these chairs are placed 
back to back the extra one gives a good place for the left foot of the 
operator, and a head-rest may thus be made of his thigh. The patient 



GENERAL PRINCIPLES 581 

should be directed to grasp the seat at both sides with his hands. At 
times it may be necessary to extract while the patient is in bed or on 
an operating table; in such cases the operator must obtain the best 
position available. Where an operating table or couch is used it is 
well, if possible, to stand at the head of the couch or table and a little 
to one side of the patient. By reaching over the head, the forceps 
shown in Fig. 576 may be used to advantage in work on the lower 
jaw; the same forceps may be used for the upper jaw by standing to 
one side of the patient. If the operator is ambidextrous, so much the 
better, as it is very advantageous to be able to use the instrument in the 
left hand, especially in extracting the teeth of the right side of the lower 
jaw; the operator in this case standing on the left side. If, however, 
only the right hand can be used, the operator should, as a rule, stand at 
the right of the chair, the left arm and hand being used in various ways 
to control the head of the patient. The mouth is opened as far as 
necessary, and the left hand is then used to hold the lips away and keep 
the jaw as steady as possible. (See Figs. 636 and 637.) In using the 
elevator, as shown in Figs. 588 and 629, for the removal of teeth from 
the left side of the mouth, especially for the lower third molar, the oper- 
ator should stand on the left side of the patient. The index finger of 
the right hand should be placed in the mouth by the lingual side of the 
tooth, and the thumb placed on the buccal side of the first and second 
molars. This gives steadiness to the jaw and lessens the risk of slipping. 

Selection and Use of Instruments. — The selection of instruments 
depends on the nature of the operation to be performed. The means 
used in extraction should be of the most simple character. Many 
deciduous teeth and permanent teeth from about which most of the 
process has been resorbed can often be easily extracted with the thumb 
and finger. Children feel less apprehension with this method than when 
an instrument is used. The thumb and fingers should be covered with 
a napkin, and the thumb placed on the inner surface of the tooth with 
the fingers against the outside of the jaw. The tooth is then forced out- 
wardly toward the cheek or lips. The roots of the deciduous teeth often 
break, but this is of little importance, for when extraction is demanded 
the roots are weakened by the natural process of resorption, and will soon 
disappear. Elevators of the various patterns shown in Figs. 588, 589, 
629, 630, and 631 should be used whenever practicable for removing 
roots, and in some cases teeth also. Fig. 588 is especially useful in 
removing the third molars, especially if they be impacted. When the 
internal anatomy of the jaws is well understood, this will be appreciated. 

Fig. 607 shows how firmly the roots are embraced at their necks 
between the two hard plates of compact tissue. It is usually impossible 
to force an instrument between the roots of teeth and these plates with- 
out breaking the internal or external walls of the latter. The cancel- 
lated tissue between these plates is, however, soft and yielding, and into 



5S2 



EXTRACTION OF TEETH 



this a properly shaped elevator can be passed between the roots. After 
pushing the instrument with the point toward the root to be extracted 
and the back toward the contiguous tooth or root, using the latter as a 
fulcrum, revolve the elevator slightly, prying at the same time, and the 



Fig. 629 




Manner of holding elevator Fig. 600. 

root will leave its socket with little or no injury to the surrounding tissue. 
Elevators should be firmly grasped and held in such a manner that 
if a breakage or slip should occur the instrument will be prevented 
from wounding the soft tissue. If root forceps were used in cases of 
this kind it would be almost impossible to avoid injuring one or the 

Fig. 630 




Elevator in use labially. 



other of the plates when removing the root. It is often advisable to 
use the forceps by passing the beaks between the plates and grasping 
the root on its proximal surfaces, instead of the external and internal 
surfaces. Even whole teeth may be extracted in this way when there 



GENERAL PRINCIPLES 



583 



are no adjoining teeth or roots. A similar plan is sometimes used in 
rapid extracting under nitrous oxid, where roots or teeth have been 
extracted on each side of a tooth, the beaks passing into the sockets 
of the extracted teeth, thus grasping the tooth to be removed on its 
proximal sides. This mode of operating must be followed with 
care, especially in teeth situated below the maxillary sinus, as the floor 
of that cavity may be easily injured. (See Figs. 604 and 605.) 



Fig. 631 




Elevator in use lingually. 

Lancing. — Lancing for extraction is not usually required, although 
there are cases where it is quite necessary. If the teeth have been 
standing alone for a long time, especially those in the back part of the 
mouth, the gums are apt to become firmly attached to them; when this 
is the case it is well to sever the connecting tissue by the use of the 
lancet before extracting. In extracting roots where it is necessary to 
remove a portion of the external plate of the alveolar process, it is well 
to make an incision in a line over the root, through the gum to the 
bone; it is even advisable to dissect the gum and periosteum slightly 
from the bone on each side of the cut. This is done in order that the 
external beak of the forceps may be passed along the bone as far as de- 
sired. By thus lancing, the parts will afterward come together and 
heal quickly, whereas if the gum is cut by the forceps it will not heal 
so well. In extracting roots in the lower jaw, if the lancing would 
cause the blood to cover the parts and obscure the operator's view, it 
should be omitted. 

Use of Forceps. — As nearly all operators are right-handed, the instruc- 
tion as to the use of forceps will be given with that understanding, 



584 



EXTRACTION OF TEETH 



most of the special instruments being made for that hand. The forceps 
are grasped in the right hand with the palm toward the body, the thumb 
on top of and partially between the handles (which will indicate to 
a great extent the amount of pressure being exerted upon the tooth), 
pressing against the handle nearest the palm just back of the joint. 
The first finger should rest a little between the handles, thus giving a 
firmer grip on the right handle (Fig. 632), which might be termed the 
fixed, or passive, handle; while the other one is the movable, or active, 
handle. Many operators do not place the first finger between the 
handles (Fig. 633). The second and third fingers pass to the outside 
of the left handle and are used to close the forceps, while the little 
finger resting between the handles is used to open the forceps, the 
thumb being used to force the beaks into the required position. After 
the forceps are in position for extracting, the first finger is placed along 
the side of the second finger to give more power to extract. 

Fig. 632 




Use of forceps. 



After it has been decided to extract by using the forceps, the par- 
ticular forms indicated must be selected and arranged in a convenient 
place, ready for immediate use as needed. Especially should this be 
the case when the operation is done under the anesthetic influence of 
nitrous oxid. It is under such conditions that the fewer forceps used 
the better; the writer generally uses but one forceps (Fig. 577) for the 
extraction of any or all teeth except the first and second molars; for 
those teeth, when the other teeth are in position, he advises using the 
special forceps. 

Having the patient's head in position, the forceps are grasped as 
previously described and the beaks adjusted to the tooth. As a rule, 
the inner beak should be placed in position first, and then the outer 
one — this is very important, especially for the lower teeth — taking care 
not to include a portion of the tongue or the soft tissues of the floor 



GENERAL PRINCIPLES 



585 



of the mouth, as both are liable to get in the way. When the forceps 
are adjusted to the inner and outer surfaces of the tooth, they should 
be forced between it and the gum until they come in contact with the 
edge of the alveolar process. It is a common error of students to use 
too much force in pressing the handles together; only sufficient force 
should be used to hold the tooth or root securely. The forceps should 
grasp as much of the roots as possible, avoiding pressure upon the 
crown and being careful not to force the beaks between the alveolar 
plates, as this would result in breaking one or both plates over the 
tooth or root extracted and also over the adjoining tooth. Cases have 
occurred in which the entire external plate of one side has been forced 
off in this way. 

Fig. 633 




Use of forceps. 



At times it may be advisable to take away a portion of the outer 
plate, in which case the lancet shown in Fig. 590 should be used to cut 
through the gum a little beyond the point of process to be removed, 
dissecting up the gum slightly; the inner beak is then adjusted and the 
outer one passed between the divided gum and the process as far as 
required; the forceps should then be closed with only sufficient force to 
cut through the bone and grasp the tooth, taking care not to crush it. 

After the forceps are in position the tooth is loosened by rotating it 
slightly if it be a round conical-rooted tooth, such as a central incisor, 



586 EXTRACTION OF TEETH 

but if it be a flattened one it should be removed by an outward and 
inward movement. 

By the "out-and-in motion" is meant that after the forceps are applied 
the force used in loosening teeth is directed in such a manner that 
the tooth is worked outward and inward from the median line of the 
mouth (see Fig. 607, in which the lines show the direction of the motion 
for each tooth). The individual teeth do not always bear the same 
relation to the median line of the jaw as shown in Fig. 607. When 
the axis of a tooth is not regular it should be loosened by moving back- 
ward and forward, and the movement should be in line with its strongest 
diameter, which lessens the danger of breaking the tooth. 

In the upper jaw the inward movement is made after the outer, but 
with not so much force, as the structure on the inner side is more dense. 

Rotation of a tooth in extracting is seldom practised, as the single- 
rooted teeth are usually flattened, and teeth that have more than one 
root cannot be rotated. Of the single-rooted teeth, the upper central 
incisors alone have roots nearly conical in shape which permit rota- 
tion as well as the out-and-in motion. A rotary motion is usually of 
advantage in extracting the roots of the upper first bicuspid when not 
double, and of the upper molars after the crowns are broken away so 
that the roots are disunited. These roots are usually round, conical, 
and somewhat curved in shape. 

If possible, the tooth should be kept in view during the operation 
so that the results of the movements may be seen. A beginner may 
let the forceps slip and extract the wrong tooth when he is not observ- 
ing each movement, but an experienced operator can depend on his sense 
of touch to a very great extent. The amount of pressure a tooth will 
stand while loosening it by an " out-and-in motion" depends on the size, 
condition, and density of the bony tissue surrounding it and the accurate 
fitting of the forceps to the tooth. Experience is the only reliable guide 
in this matter. When a tooth resists ordinary effort, if the operator is 
not quite sure of the cause of the resistance of the tooth, it is better to 
desist temporarily and allow the patient to rest, in order to investigate 
the condition of the tooth and its surroundings. Fig. 61 9 will give some 
idea of the causes of the resistance offered by apparently normal crowns. 

After the forceps are applied and the tooth slightly moved, if the 
operator has a cultivated sense of touch he will feel that the tooth is 
yielding in one particular direction; as a general rule the tooth should 
be carried in that way. 

The force applied to extract teeth safely and judiciously should be 
made with arm and wrist motion; if the whole body is used the sense 
of touch is blunted and accidents are liable to occur. 

Extracting Deciduous Teeth. — In extracting the deciduous teeth the 
principles involved are nearly the same as for the permanent. A care, 
however, must be taken that is not necessary with the permanent 



INDIVIDUAL PERMANENT TEETH 



587 



teeth, i. e., to avoid injuring the developing permanent teeth that are 
situated immediately beneath them. 

Fig. 634 shows all the deciduous and the developing permanent 
teeth except the third molars. It gives a true idea of their relative 
positions. Special attention is drawn to the position of the crowns 
of the bicuspids as related to the deciduous molars. This is also well 

Fig. 634 




Skull of a child, about six years of age, showing all the deciduous teeth in position and nearly all 

the developing teeth. 

shown in radiogram Fig. 648. It will be seen that they are situated 
between the roots of the latter teeth, and by using undue force in adjust- 
ing the forceps these crowns could easily be misplaced, extracted, or 
injured. 

If the deciduous teeth are extracted at the proper time they can 
usually be removed by the thumb and fingers as described. If not, one 
of the forceps shown in Figs. 576 and 577 should be used. 



EXTRACTION OF INDIVIDUAL PERMANENT TEETH 



The anatomy of the individual teeth and the majority of their often- 
repeated variations, as well as the general principles governing the 
extracting operation being understood, the extraction of each tooth will 
now be studied, those of the upper jaw being first considered. 

The Upper Teeth. — The Central Incisor. — This tooth has a strong, 
round conical root. The forceps are carried into position by placing 



588 EXTRACTION OF TEETH 

the inner beak at the palatal surface of the neck of the tooth; the outer 
one is then placed in position and the instrument forced upward with 
a slight rotary motion between the gum and the tooth until it comes 
in contact with the alveolar process. As the root is round and conical, 
it is loosened by rotation and the out-and-in motion and then removed 
by drawing it directly from its socket. It is, as a rule, easily extracted. 

The Lateral Incisor. — This tooth is much smaller than the central. 

The root is flattened and somewhat curved, the apex being often bent 

in the direction of the canine teeth. After applying the forceps as directed 

for the central incisor, the motion should be outward and inward. As 

the tooth has a delicate root, the force used must 

Fig. 635 De light. When loosening and removing it, care 

£l fe^ P- x must be exercised, as its root is not straight. 

/ \ I ^ The tooth is carried in the direction of the least 

| I | r ** '* resistance, which is usually toward the canine 



\ tooth. 



The Canine. — This tooth is usually more firmly 
Canine, lateral, and cen- set in the jaw than any other, and it often requires 
trai incisor extracted from considerable force to break up its attachments. 

maxillary sinus that were rr , 1 ., . . . . , . n , .„ 

causing neuralgia. I he root is long and slightly flattened. Alter 

applying the forceps its attachments are broken 
up by the out-and-in motion. After loosening it is usually easily re- 
moved from its socket. As this tooth is erupted after the adjoining 
teeth are in position, it is often malposed. If the deciduous canine has 
been lost before its proper time, and the first bicuspid has pushed 
forward, there is no room for the canine to take its true position. This 
irregularity varies to a great extent. The canine may also be out of 
position from unknown causes. A marked specimen is seen in Fig. 
628, where both canines are impacted. They were entirely covered by 
a bony lamina. (See also Fig. 644.) 

Sometimes the roots of these teeth project into the maxillary sinus, 
or even into the nasal chamber, while the crowns are impacted be- 
tween the palatal plate and the plate forming the floor of the nose. 
Fig. 635 represents a canine, lateral and central incisor, which were 
extracted from the sinus, the roots being embedded in its inner wall. 
Teeth thus impacted are often a source of trouble in various ways, 
and when discovered should be removed. When the tooth is so covered 
by bone that the forceps cannot be applied the bone must be cut away 
sufficiently to allow the forceps to grasp it. A very good instrument 
for removing the bone in the upper jaw is the elevator shown in Fig. 588; 
after the point has been sharpened it may be used as a chisel or gouge. 

The Bicuspids. — The first bicuspid usually has a bifurcated root, 
and the only motion that can be used safely for loosening is the out-and- 
in, as these roots are sometimes considerably divergent. The removal 
after loosening is not always easily accomplished, a little outward 



INDIVIDUAL PERMANENT TEETH 



589 



pressure being frequently necessary. If the force required is used too 
suddenly the inner root is liable to break. 

The second bicuspid usually has a single flattened root, though occa- 
sionally it is bifurcated. The motion used to loosen this tooth is the 
outward and inward, using the same precaution as with the first bicus- 
pid on account of the possibility of a double root. 

Fig. 636 




Showing position for extracting upper teeth of left side. 



The First and Second Molars. — These teeth are nearly similar, having 
three roots, two buccal and one palatal, which vary so much in degrees 
of separation that no set rule can be given for their extraction. The 
roots of the first are usuallv more divergent than those of the second. 
Only the out-and-in motion can be used, rotation being out of the 
question in loosening them, as the roots often diverge to a great extent. 



590 



EXTRACTION OF TEETH 



(See Fig. 627, p.) After the tooth has been loosened there is at times 
a difficulty in removing it, on account of the distance around the three 
roots; owing to their divergence this distance is greater than the size 
of the anatomical neck of the tooth corresponding to the opening of the 
socket. The only general rule that can be given is to carry it in the 
direction of the least resistance. Each tooth has more or less of an 
individual character, and therefore the operator must be governed by 
circumstances. The main precaution to be observed is not to be in too 
great haste, as there is danger of breaking one of the roots or removing 
a large piece of the outer plate of the alveolar process. (See Accidents, 
p. 606.) 

Fig. 637 




Showing position for extracting upper teeth of right side 



The Third Molar. — This tooth so varies as to the shape and number 
of its roots that it is seldom spoken of as an abnormal tooth, no matter 
in what form or position it may be found ; the greater number have roots 
curved backward and outward. Their position in the jaw also varies 
considerably. The forceps shown in Fig. 576 is the instrument to use 
in extracting. After the forceps have been firmly placed the principal 
motion is the out-and-in, though more out than in. If there is much 
resistance the hand should be carried outward and upward, or in the 
direction of the least resistance. This tooth is sometimes erupted at 
the side of the alveolar process (Fig. 638), with its occlusal surface 
pointing toward the cheek. (See Figs. 645 and 646, radiograms made 
from the specimen shown in Fig. 638.) It is not well to have the mouth 



INDIVIDUAL PERMANENT TEETH 



591 



opened too far, as it brings the coronoid process of the lower jaw in the 
way. 

In stating the general rules of extracting, caution was given not to 
make the movements faster than could be seen; this applies very par- 
ticularly to the third molar. It is so near the ascending ramus in the 
lower jaw that it is possible, especially when the roots are curved and 
spread out, to fracture this angle, or in the upper jaw the tuberosity may 
be broken away, thus opening into the maxillary sinus. The gum tissue 
often adheres to the posterior portion of this tooth; when this hap- 
pens it is best to desist from attempts at extraction and sever the tissue 
from it with a curved lancet or scissors before removing the tooth with 
the forceps, or, as before advised, dissect the gum away before applying 
the forceps. 

Fig. 638 




An impacted upper third molar. A similar condition found on the opposite side of the skull. 



The Lower Teeth. — As a rule, the teeth of the lower jaw are more 
difficult to extract than are those of the upper jaw, the lips and cheeks 
being in the way. The tongue is also troublesome, covering the tooth, 
and when the inner beak of the forceps is placed in position special 
care must be used to prevent part of the tongue or floor of the mouth from 
being caught in the instrument. 

The Oral or Anterior Teeth. — (For position see Fig. 639.) — These six 
teeth have small single, straight, compressed roots. Their extraction 
is only necessary when they become loosened by accident or from 
disease, or when it is necessary to clear the mouth for inserting artificial 
teeth. The operator should stand a little back and to the right side of 
the chair, being somewhat elevated above the usual position. Pass the 
first finger of the left hand between the lips and the alveolar border, 
and place the remaining fingers beneath the chin with the thumb on 
the inside of the teeth. For the incisors use the lower root forceps 



592 



EXTRACTION OF TEETH 



shown in Fig. 587 or the universal forceps shown in Fig. 577. The 
canines are larger and more firmly set; delicate root forceps, therefore, 
are not usually suitable; the instrument shown in Fig. 577 or, better, 
the bicuspid forceps (Fig. 585) are much to be preferred. An out-and-in 
motion is proper for loosening all these teeth. 



Fig. 639 




Showing position for extracting lower anterior teeth. 



The Bicuspids. — The lower bicuspids have compressed roots seldom 
bifurcated, and are generally extracted by the out-and-in motion. The 
special forceps for these teeth should be made so that they grasp a con- 
siderable portion of the surface of the tooth. These teeth are often 
difficult to extract without breaking when all the teeth are in position, 
the roots being long and narrow and often situated in an awkward 



INDIVIDUAL PERMANENT TEETH 



593 



position. As shown in Fig. 606, the position of the roots of the second 
bicuspid is a little to the inner side of the anterior root of the first molar. 
The tooth illustrated in this particular case would be very difficult to 
extract without breaking. 

The First Molar. — (For position see Fig. 640 for the left side, 641 for 
the right side.) 

The first molar, if in a mouth where all the teeth are in position, is 
generally the most difficult of all the teeth to extract. The roots are 
usually long and diverging. It is lower in the arch than the other teeth, 
and is in fact similar to an inverted keystone; consequently, when 

Fig. 640 




Showing position for extracting lower teeth on the left side. 



extracted it is drawn through the arch. When the teeth are close together 
the second bicuspid and second molar yield a little, but great care 
must be taken that one or both of these teeth are not extracted with 
the first molar. In placing the forceps on the lower molars the points 
of the beaks of the special molar forceps (Fig. 573 or 586) are placed 
in between the roots on each side of the tooth. Care should be exer- 
cised to avoid including a portion of the tongue or soft tissues of the 
floor of the mouth in the forceps. If the forceps are not well placed 
the wrong tooth may be extracted, as it is possible for them to slip in 
between two teeth. 
38 



594 



EXTRACTION OF TEETH 



In loosening these teeth the out-and-in motion is used, and as they are 
wedged in it is often necessary to continue this motion while extracting 
them from their sockets. At times it is advisable to move the tooth out- 
wardly after it has been slightly lifted from its socket. Occasionally the 
roots diverge so far that either the crown has to be broken from the 
roots at their bifurcation or the tooth divided in the line of bifurcation 
with splitting forceps; each root being then extracted separately. 

The Second Molar.— The roots of this tooth are not as diverging 
as those of the first molar, as may be seen by examining Fig. 602, nor is 
the tooth wedged in as tightly as in the case of the first molar. 

The out-and-in motion is required for these teeth, using the same 
precautions that are necessary in the extraction of the first molar. 

Fig. 641 




Showing position for extracting lower teeth of the right side. 



Ill 



The Third Molar. — In this tooth the roots may vary so much 
number and shape that it can hardly be said to be a typical third molar. 
Fig. 602 shows what might be called a typical third molar, but these are 
only found in well-developed jaws, where the teeth are not so large as 
to cause crowding, or where there has been no inflammatory condition 
causing excessive deposit of lime salts within the cancellated tissue. 
They vary in character from the one shown in Fig. 602 to those shown 
in Figs. 613 to 624 inclusive. There are also third molars having three, 



INDIVIDUAL PERMANENT TEETH 595 

four, or five roots. In Fig. 627, a shows another form of the third molar; 
b, c, d, e, and / show where the third molar has united with the second 
molar; g and h illustrate three molars united; i, j, k, I, m, n, o, and p 
show variations of roots. The positions these teeth occupy may vary 
in all degrees from that shown in Fig. 602 to those shown in Figs. 613 
to 624 inclusive. 

Where the third molar is in the position shown in Fig. 602, and there 
are no other complications, its extraction is easy. The tooth is removed 
by placing either the special lower molar forceps shown in Fig. 586 or 
the forceps shown in Figs. 576 and 577 in position, and using the out- 
and-in motion with a slight raising of handles. If Fig. 576 be used the 
beaks should be turned downward and the handles carried upward. 
But when it is of irregular form and position, as shown in the various 
illustrations, the difficulty increases with the degree of variance from 
that of the typical tooth shown in Fig. 602. These cases should be 
closely studied. If portions of the teeth are in view, as shown in Figs. 
619 and 620, they will assist to some extent in the diagnosis of the posi- 
tion of the roots. In this particular case the bone as well as the roots 
being much hypertrophied, it would be impossible to extract the roots 
without fracturing the process to a greater or less extent. It will be 
noticed, on examining the section Fig. 619, that to have fractured the 
inner portion of the jaw, the inferior dental nerve and vessels and also 
the mylohyoid nerve and vessels would be endangered. If in attempt- 
ing to extract this tooth it should not yield to a pressure which if in- 
creased would break the bone, it is better to desist and cut away the bone 
with a bur (shown in Fig. 651) in the surgical engine, as was done in the 
case of the specimen from which the illustration was made. 

The Extraction of Malformed and Abnormally Placed Teeth. — The 
term " impacted teeth" is generally used to designate permanent teeth 
which are abnormally placed or have failed wholly or partially to erupt. 
It is also sometimes employed to indicate the retarded eruption of 
deciduous teeth. 

Order of Frequency of Abnormally Placed Teeth. — The experience of 
the writer has been that the order of frequency of impacted teeth is 
as follows: First, the lower third molar; second, the upper canines; 
third, the upper third molar; fourth, the upper central incisor; fifth, 
the lower second premolar; sixth, the upper second premolar; seventh, 
the lower canine. 

Diagnosis. — Many malformed and abnormally placed teeth are entirely 
hidden from view, and those in which the crowns are partially seen 
give only a suggestion of the cusps while the shapes and positions of their 
roots are difficult to diagnosticate. In order that the extraction may be 
intelligently made, a forty-five degree angle hatchet-shaped excavator is 
one of the most useful instruments to use as a probe to determine the 
position of the crowns and roots, especially when used by one experienced 



596 



EXTRACTION OF TEETH 



in the handling of such an instrument and who is thoroughly conversant 
with the normal and pathological anatomy of these parts. No one with- 
out this knowledge is properly equipped to diagnosticate such malposed 
teeth, much less to extract them. 

The improvement of radiography, especially in the technique of its 
dental application, has been so rapid and its results so accurate, that 
the use of the a;-ray in the diagnosis of impacted teeth has become 
indispensable, especially in cases where none of the tooth is exposed to 
view. 

Figs. 614 to 624 inclusive are made from photographs showing some 
of the positions in which lower impacted third molars are found. These 
illustrations were made from cleaned specimens. Fig. 638 shows the 
crown of an impacted upper third molar where a portion of the bone has 
been removed. 



Fig. 642 




Radiogram of mandible, showing rudimentary fourth molar 



Fig. 622 is made from a radiogram of both halves of the bone of the same 
boiled or cleaned mandible. It shows two deformed and misplaced 
lower third molars. In the upper picture the tooth is nearly in a hori- 
zontal position with its occluding surface well "locked" under the 
posterior surface of the second molar. It will be noted that the roots 
are curved upward and backward above the inferior dental canal or 
tube. The roots of the second and third molars are enlarged by the 
irritation resulting in the overactivity of the cementoblasts, the crown 
of the second molar is tipped backward, probably from the pressure 
of the anterior cusp of the third molar. In the lower picture the third 
molar seems to be in line to take its proper place but its anterior cusps 
are caught under the crowns of the second molar and the solid bone 
posterior to it prevents it from taking its normal position; the roots 
of this third molar extend below the line, and to the lingual side, of the 



INDIVIDUAL PERMANENT TEETH 597 

inferior dental canal or tube. The roots of the three molars are enlarged 
by an extra deposit of eementum. 

Fig. 642 is made from a radiogram of a cleaned specimen, which shows 
an impacted rudimentary lower fourth molar The roots of the second 
and third molars are thickened, the surrounding tissue being more 
dense than normal. These conditions are difficult to diagnosticate in the 
living subject and are best revealed by a good radiographic plate 

Fig. 643 is made from a radiogram of a cleaned specimen which shows 
a lower tooth in the ramus of the jaw. 

Fig. 644 is made from a radiogram of a cleaned skull which shows an 
impacted upper right canine tooth lying across the roots of the central 
and lateral incisors, also in close juxtaposition to the roots of the first 
and second premolars. The end of the canine root is in the wall of the 
maxillary sinus. 

Figs. 645 and 646 are two pictures made from radiograms of a cleaned 
skull (see Fig. 638). They show two impacted upper third molars, 
one on each side of the jaw. Fig. 645 shows them apparently in close 
relation, while in Fig. 646 they are wide apart. The cause of this apparent 
difference of position is that in the first picture the teeth on the opposite 
sides of the jaw are nearly in a line with the anode or target of the 
x-ray tube, while in the second picture the tube is placed a little farther 
back, causing the impacted tooth and the teeth nearest that side to be 
thrown forward, apparently placing the impacted tooth in the maxillary 
sinus. It requires some practice to read correctly pictures of this' kind 
and avoid an error of diagnosis due to an optical illusion such as that 
shown in the case here illustrated, the teeth that show most distinctly are 
those that are nearest the plate when the radiogram was taken. "When 
there is an impacted tooth or teeth in each side of the jaw it is necessary 
to take two pictures, one radiogram placing the plate on the right side 
and another one with the plate on the left side. In film pictures the 
confusion of the sides is avoided, but it is almost impossible to obtain a 
radiogram on a film of so highly placed impacted teeth as in this case. 

Fig. 647 is made from a radiogram of a patient, showing a rather 
common case of impacted lower third molar, also an upper right molar 
that has not erupted into its normal position. ^Yhen the plate of this 
picture is carefully examined there is shown to be a condition in the 
opposite side similar to those shown in Figs. 645 and 646, which made 
it necessary to have another plate made to give a clearer view of the 
other side of the jaw. 

Fig. 648 is made from a radiogram of a patient about the age of 
ten. This picture shows the lack of development of the lower left 
second and third molars; it also shows that the upper second molar is 
in a false position with no germ of the third molar showing. The decid- 
uous premolars are shown immediately over the permanent premolars, 
bicuspids, which demonstrate that in extracting deciduous teeth the 



598 



EXTRACTION OF TEETH 



forceps must not be forced down below the crowns. The same conditions 
are shown in Fig. 634. 



Fig. 643 




Showing tooth malposed in ramus of the mandible. 
Fig. 644 




Radiogram showing impacted canine. 



INDIVIDUAL PERMANENT TEETH 

Fig. 645 



599 




Radiogram showing impacted third molars. 
Fir,. 646 




Same case as Fig. 645, taken from different angles. 



600 



EXTRACTION OF TEETH 



Fig. 649 is made from a radiogram film, it shows an impacted lower 
third molar. This tooth is in such a position that its occluding surface 
can be cut away with a disk. 

Fig. 650 is made from a radiogram film; it shows a lower third molar 
impacted below the second molar, apparently advancing between the 
second and first molar. The patient was suffering not only in the 
immediate region, but also in the surrounding parts of the temporo- 
mandibular articulation. Extraction of the first molar was all that 
was necessary to produce almost instant relief, and the third molar 
soon began to advance to the position of the first. 

Fig. 647 




Showing impacted lower third molar and malposed upper molar. 



Abnormally placed teeth usually give considerable trouble, if not in 
early life, they do later on, the seriousness of this disturbance depending 
largely upon the location and malformation of the misplaced tooth 
and upon the general conditions of the patient. If left impacted these 
teeth are liable to prevent the proper nourishment of other teeth, as 
shown in Figs. 615 and 628. They are also liable to press upon the 
branches of the fifth pair of nerves, producing severe neuralgia not only 
in the locality of the lesion, but in remote parts. They are also liable 



INDIVIDUAL PERMANENT TEETH 601 

to bring about inflammatory conditions of this region, producing cellu- 
litis in the tissues of the mouth, neck, and throat. They interfere with 
the temporomandibular articulation, cause disturbances in the nasal 

Fig. 648 




Same case as in Fig. 647, taken from a different angle. 
Fig. 649 Fig. 650 





Impacted lower third molar. Impacted third molar below the second molar. 

cavity and the associated pneumatic sinuses and cells, and even interfere 
with hearing. They may even contribute to the production of malig- 
nant growth of the bone and surrounding tissue. 



602 EXTRACTION OF TEETH 

Many cases could be cited where serious pathological conditions have 
been produced, such as chorea; also various degrees of mental disturb- 
ances, even insanity, which have been relieved by the treatment of 
removal of malposed teeth. The conditions under which these teeth are 
formed vary so much that the same rules for extracting under ordinary 
circumstances cannot be applied to them except in a general way. 
After the diagnosis of the character and position of the tooth has been 
made, then the operation is to be planned out. As a rule, the offending 
tooth should be removed or liberated without, the sacrifice of any other 
teeth, but there are cases in which other teeth should be extracted. 
There are several points to be considered: The character of the tooth 
and its position, the character of the adjoining teeth, age, and general 
health of the patient. 

When the impacted tooth can be brought into useful position by the 
removal of causes impeding its eruption, the necessary steps should 
be taken for its liberation, occasionally it will be found advisable to 
extract teeth other than the impacted one, thus allowing the retarded 
teeth to erupt into the place of the extracted one. For example, there 
are cases where a lower or upper third molar will erupt into the place of 
an extracted second molar. Then again in cases similar to those shown 
in Fig. 615 and 638 one should not extract the impacted tooth without 
first extracting the second molar as the danger to the surrounding tissues 
and bone necessarily incident to the removal of the impacted tooth is 
too great. 

The surgeon must, of course, save teeth where he can, but it is more 
important to conserve surrounding tissues and avoid injury to the jaws. 
In other words where grave pathological sequelae of impacted teeth are 
present or imminent, it is more important that these consequences should 
be cured or avoided than that a tooth or teeth otherwise useful should 
be retained. 

The following descriptions will cover the general procedure of extract- 
ing ordinary forms of impacted lower third molars. (See Figs. 621, 622, 
and 650.) If the teeth are well up and the crowns are exposed so that 
the occluding surface can be cut away it should be done with a car- 
borundum disk, which will " unlock" the third molar from the second, 
then if the bone overlying the roots is not too dense the tooth can be 
lifted from its socket by the use of an elevator (Fig. 588) ; if, however, 
the bone is dense, it must be cut away until the remainder will yield 
to the pressure from the elevator. In teeth like those shown in Figs. 
615 and the upper picture of 612 it would be impossible to use the disk 
to unlock the tooth without injuring the surrounding tissues. In Fig. 
615 it would be advisable to extract the second molar, as it is badly 
decayed and devitalized, although it is more than likely that in this 
particular case the third molar would not ascend to a serviceable position. 
In lower picture (Fig. 622) the writer would recommend the extraction of 



INDIVIDUAL PERMANENT TEETH 



603 



Fro. 651 



the second molar, as there is every probability that the third molar would 
then become a useful tooth. In those cases where the use of a disk will 
not unlock the third molar and it is not desirable to extract the second, 
the process of removing the impacted third molar becomes a more 
serious operation, and, as a rule, should be done in a hospital, where all 
conveniences and assistances are at hand, for the removal of some 
impacted teeth is more difficult and serious than 
even some of the major operations of general sur- 
gery. The patient should be etherized, a mouth gag 
fixed in position, and a portion of the soft tissue re- 
moved with a small knife; then using a revolving 
spiral osteotome (Fig. 651), operated by the surgical 
engine, the bone covering the greater portion of the 
tooth can be cut away until- the elevator will lift the 
tooth out of its bed. It is sometimes better to cut 
through the crown or neck of the tooth until it is so 
weakened that when the elevator is forced under the 
tooth, it will break at this point. This would allow 
each portion to be removed. When it is impossible 
to force the elevator (shown in Fig. 629) between 
the bone and the tooth, a space can be made by 
pushing a revolving osteotome between the tooth and 
the bone, cutting a portion of each, which will make 
sufficient opening for the use of the elevator. 

The writer now seldom uses the forceps to remove a tooth after 
loosening it with the elevator. In using the elevator on the left side, it is 
operated with the right hand, the surgeon standing on the left side of the 
patient. The left forefinger is placed in the mouth, by the lingual side 
of the tooth, and the thumb is placed on the buccal side of the first and 
second molars. This gives steadiness to the jaw and lessens the risk 
of slipping. As the tooth is raised from its socket, the forefinger is 




Two forms of Cryer's 
spiral osteotome. 



Fig. 052 





A b 

Showing three views of a lower three-rooted molar tooth 




placed so as to bring the tooth out of the mouth. If the tooth to be 
removed is on the right side, the elevator should be used with the left 
hand if possible (the surgeon standing on the right side). If the operator 
must use the elevator with his right hand, he should, however, manage to 
guard and steady the parts with his left hand. 

Fig. 652 is made from three photographs of a lower three-rooted 



604 



EXTRACTION OF TEETH 



molar tooth after extraction. A shows the outer or buccal side of its 
roots, in about the same position as when in the jaw. The posterior 
cusps were broken away in a former endeavor to extract it. The greater 
portion of the crown was cut away with the surgical engine. On the 
side of the tooth there is a groove extending backward, downward, 
and inward, cut by the osteotome. It was along this groove that the 
elevator was forced under the tooth, causing the slight remaining portion 
of the crown to fracture. In B the tooth is turned slightly outward, in 
order to show three roots and the line of fracture which liberated the 
tooth. In C the tooth is turned upon its buccal surface, showing the two 
anterior cusps which were locked under the distal surface of the second 
molar. 

Fig. 653 




Showing the direction in which the lower third molar is to be extracted. 



In Fig. 613 the third molar is in such position as to be easily extracted, 
though if proper care were not used the extraction might have serious 
consequences. It will be noticed that the points of the roots are just 
through the inner U-shaped cortical portion of the lower jaw below 
the mylohyoid ridge and project into the submaxillary region. Now, 
should this tooth or the roots be pushed downward in attempted ex- 
tracting, as is sometimes taught, it might be forced into the submaxillary 
region and consequently be lost for a time, with the possibility of having 
to perform a subsequent surgical operation to cut it out from the neck. 

An impacted third molar often causes great distress by initiating an 
inflammation which extends to the region surrounding the angle of the 
jaw, and often including the temporomaxillary articulation and soft 
parts within the mouth. Under these conditions the jaws can only be 
partly opened, deglutition is impaired, and solid food cannot be taken. 
If any part of the tooth can be seen, the difficulty is not so great. Relief 
must be given, and, as a general rule, the offending tooth should be 
extracted. Circumstances may arise in which the removal of the second 



TREATMENT AFTER EXTRACTION 605 

molar may become an unavoidable preliminary to the removal of the 
third molar. As the mouth can only be opened slightly, it is impossible 
to use the large special molar forceps. An elevator is sometimes recom- 
mended in these cases, but it may prove to be a dangerous instrument 
to use under such conditions, for when the tooth is lifted out of its posi- 
tion in the mouth, it might slip back into the larynx. It is well in some 
cases to loosen a tooth with an elevator and then remove it with the 
forceps shown in Figs. 576 or 577, as they are small, and are so shaped 
that the beaks may be carried back to the tooth mainly along the vesti- 
bule of the mouth, the inner blade being placed between the teeth by 
passing the forceps back of the second molar. Often it is impossible 
to see completely what is being done; therefore it is not well for a beginner 
to undertake this kind of extracting. After the forceps are in position 
the tooth should be worked in any direction in which it will yield; this 
is generally outward, upward, and backward, in the manner of unfasten- 
ing a hook (Fig. 653). When the lower third molar is impacted near 
the gonion or external angle of the jaw, it may be necessary to open it 
from the outside through the soft tissues. When such is the case the 
surgical engine should be used for cutting the bone. 



TREATMENT AFTER EXTRACTION 

The operator should recognize immediately any accident that may 
have happened during the operation of extraction, and treat it as the 
circumstances indicate; but if nothing unusual occurs, then the patient 
may be allowed a few moments' rest, after which the mouth should be 
carefully examined. If there be any loose portions of the process or 
pieces of gum hanging to the parts operated upon, they should be 
removed by any convenient means, such as small forceps, a curved pair of 
scissors, or a curved lancet (Figs. 590 and 592). 

When several teeth have been extracted, leaving ragged edges of the 
outer walls of the alveolar process, these should be removed with the 
excising forceps, or, better still, by the use of either forceps Fig. 576 or 
577, according to circumstances, as the beaks can be carried between the 
gum and the process better than can the blades of the excising forceps. 

An antiseptic mouth wash, consisting of a tablespoonful of phenol- 
sodique to a glass of water, should be used several times daily for the 
next few days. Any other suitable antiseptic mouth wash which may 
be more agreeable to the patient may be used instead, although the 
phenol-sodique is highly efficacious. 

Occasionally, in a few days after extraction, pain will be noticed in 
and about the alveolus, especially when the tooth has been the seat of 
pericemental inflammation. Relief in such a case is usually given by 
removing any clot that may have formed, and breaking down the 



606 



EXTRACTION OF TEETH 



degenerated tissues which should have adhered to the root. A pledget 
of cotton saturated with the full-strength solution of phenol-sodique or 
campho-phenique should then be inserted as a dressing. 



ACCIDENTS 



When accidents of any kind whatever occur, the operator should be 
calm and appear perfect master of the situation. He should be pre- 
pared to deal successfully with whatever conditions may arise. 



Fig. 654 



Fig. 655 



Fig. 656 






Fig. 65/ 



Fig. 658 



Fig. 659 






Fig. 660 



Fig. 661 



Fig. 662 






One of the most common accidents is the breaking of a whole or 
portion of a tooth or root. If the operator has any doubt of his ability 
to remove the tooth entire, he should inform the patient that there is a 
possibility of its breaking, in which case not to be alarmed. If the 
tooth is removed without breakage, so much the better; even if it does 
break, it will not cause alarm to the patient. It is more desirable that 
all of a tooth should be removed, for if its surrounding membrane has 
been inflamed, or if a root having a portion of the pulp attached has 
been broken, either will be the source of obstinate pain. 



ACCIDENTS 607 

It is better, however, under some circumstances to let certain roots 
remain if they are broken than to break away a large amount of process. 
Roots are sometimes so situated that they may be easily forced into the 
maxillary sinus (see Figs. 604 and 605), or into the submaxillary region 
(see Fig. 613), or upon the inferior dental nerve. If there exist reasons 
for believing that the root will not cause undue pain, and there be 
danger of breaking a large amount of process, it is preferable to let it 
remain, as in a short time the contraction of the soft parts and their 
expulsive efforts will force the root outward, and it may then be removed 
without danger. If roots are forced into the maxillary sinus they must 
be followed and removed. 

When several teeth are to be extracted under an anesthetic, if the 
gum should adhere unduly to one of them, the operator should desist 
from its removal and proceed with the other extractions, after which 
the adherent gum should be severed with a curved lancet or a pair of 
curved scissors and the tooth then removed. If the gum be much 
torn and the bone exposed to a great extent, it should be held in place 
by a few interrupted sutures. If, however, proper care be taken in 
extracting, this should not occur. 

In extracting crowded teeth, or those having frail alveolar surround- 
ings, it is possible to remove a piece of the alveolar plate, especially in 
extracting the first and second molars, the broken piece extending back- 
ward, forward, or in both directions to the adjoining tooth (see Figs. 
654 to 662). The tooth in front may even be partially lifted from its 
socket. As soon as the operator sees the impending accident he should 
either stop and see if his method of extraction could be improved, or, 
this point being negatively decided, hold the parts in position with the 
left hand as well as he can, and after the tooth is removed force the 
injured parts into position; they will usually stay, but if not, appropriate 
appliances should be used for retention. 

In extracting the upper third molar, the tuberosity is sometimes 
broken away, opening into the maxillary sinus (see Figs. 654, 655, 656, 
659, and 662, showing where teeth have been carried away with the 
tuberosity). If it is a simple fracture the parts should be forced into place 
and they will in a short time reunite. But if the parts are torn loose it 
will be of little use to try to replace them; the best course is to trim 
away the ragged edges, using the curved scissors for that purpose. 

After such a fracture it is possible that hemorrhage may occur from 
rupture of the superior dental artery. This is sometimes difficult to 
control. One of the best remedies, however, is to pack the parts tightly 
with medicated gauze. This application must be left in for a few days 
and then be carefully removed. It is sometimes well to take out only 
part of the gauze at a time, the loosened portions being cut off with a 
pair of curved scissors. Hemorrhage after extraction usually ceases 
in a short time, and then there is no occasion for treatment; when, 



60S 



EXTRACTION OF TEETH 



however, the adjoining parts are much inflamed, or if the patient is in an 
anemic condition, or the case is one of hemorrhagic diathesis, special 
treatment will be necessary. 

Hemorrhage of extraction may be divided into two classes, arterial 
and capillary. When arterial, it is usually located in the socket of 
the tooth, and may usually be stopped without much difficulty by taking 
a twist of absorbent cotton, shaping it into a thin tapering roll, and 



Fig. 663 





Barton's head bandage. 



Fig. 664 



thoroughly packing the socket. Before inserting the cotton tampon, 
it should be rolled in tannic acid until the fibers will hold no more, 
then the cotton is to be packed tightly into the alveolus with a dental 
plugger. In packing the cotton it is well to begin at one end and crimp 

it upon itself until the socket is entirely filled. 
The plug in a few cases may require retention 
in position by compression. This is accom- 
plished by holding a few folds of muslin or 
similar material over the plug, closing the 
mouth and binding the jaws together with a 
few turns of a Barton's bandage (Fig. 663). 
The 25 per cent, ethereal solution of hydrogen 
dioxid in small quantity on cotton packed 
into a bleeding socket is a most efficient styptic, and will effectually 
control severe hemorrhage after extraction. Care must be exercised 
not to use the solution in excess, as it may cause injury to adjacent 
parts. 

When hemorrhage occurs from the surrounding tissue, as in patients 
in an anemic condition or in cases of hemorrhagic diathesis, the case 
usually falls into the hands of a general practitioner for systemic treat- 




Showing compress and ligatures. 



ACCIDENTS 609 

ment, but the local treatment usually employed by physicians in these 
cases is often unsatisfactory, many using MonsePs solution of per- 
sulfate of iron, which, although it may be a good styptic for use in other 
parts of the body, should not be used in the mouth. The local treat- 
ment in such cases, whether soon after extracting or not, is first to 
remove all clots from the wound and find the exact place or places 
from which the blood is exuding. A suitable styptic and compression 
are the principal means used for stopping it, the latter perhaps being 
the most important. Tannic acid applied on cotton, lint, or similar 
substances is an excellent styptic for this use. Compression can be 
applied as the ingenuity of the operator may direct. When a hemor- 
rhage occurs from a socket between sound teeth, it can be readily con- 
trolled by two ligatures, making one fast to each tooth, then placing in 
position and tying the four ends together over the compress, as shown 
in Fig. 664. In a few rare cases an impression of the parts should be 
taken in wax or modelling compound in order that a vulcanite or metallic 
plate can be made to hold the styptic compress in position. After the 
compress is in position warmed modelling compound can be placed 
over it and the jaws brought together and retained in place by a head 
bandage. A plug of hardening plaster of Paris may be made and 
forced into the bleeding socket in obstinate cases, or in extremis the 
extracted tooth might be soaked well in phenol-sodique and reinserted. 
A very efficient local hemostatic is a 1 to 1000 solution of adrenalin 
chlorid. A piece of iodoform gauze moderately soaked in this solution 
and packed in the tooth socket will often control severe hemorrhage. 
This drug acts by causing constriction of the bloodvessels. It is the 
most powerful vasoconstrictor known, although its effects do not last 
long. 

The systemic treatment is often important; if the patient is seen 
to be anemic or known to be of the hemorrhagic diathesis, the treat- 
ment should be begun before extracting. This is done by thoroughly 
building up the system by a course of hygienic and tonic treatment. 
The cause of bleeding in cases where the hemorrhagic diathesis exists 
is but imperfectly understood; the blood may be so defibrinated that it 
has lost the power of coagulation and so will not form a clot, or the 
muscular coats of the vessels have lost their tonicity, either through 
general debility or the lack of energy in the vasomotor nervous system, 
which prevents their contracting so as to close the lumen. Certainly 
the walls of the capillaries permit free transudation of the blood. In 
good health the proper coagulation and the contraction of the blood- 
vessels will stop the hemorrhage even when an artery of considerable 
size is lacerated, especially if the flow be held in abeyance by artificial 
means for a short time. It is when the blood will not coagulate and 
the vessels fail to contract that a thorough systemic treatment must 
be given. This lack of normal function on the part of the blood and 
39 



610 EXTRACTION OF TEETH 

vessels may arise from various diseases, and in order to treat judiciously 
a patient exhibiting the hemorrhagic diathesis, a thorough examination 
must be made and such treatment given as the diagnosis indicates. 
Among the most common causes of hemorrhage are anemia, syphilis, 
purpura, tuberculosis, and a generally impaired vitality, rarely an over- 
acting heart, the passive hyperemia attendant upon a weak heart is a 
potent factor requiring a course of preliminary treatment. 

Specific and special diseases must of course receive the treatment 
peculiar to these conditions. On general principles the following tonics 
are advisable: Quassia, cinchona and its alkaloids, iron in its various 
forms, sulfuric and hydrochloric acids, arsenic, phosphorus, nux vomica 
and its alkaloid strychnin. Of general or constitutional hemostatic 
remedies, the best are certain salts of calcium, such as the chlorid and 
the lactate, and of magnesium such as the carbonate. They act by 
increasing the coagulability of the blood. It must be remembered, 
however, that an excess of calcium salts tends to reduce the coagulability 
of the blood, so that prolonged use of these drugs may do more harm 
than good. A combination of these seems to be more effectual than 
calcium chlorid alone. Thirty grains of calcium chlorid or lactate 
with thirty grains of magnesium carbonate may be given as an initial 
dose followed on succeeding days by fifteen grains of each drug or five- 
grain tablets of extract of thymus gland may be given up to twenty a 
day to supply the nucleo-albumin necessary for coagulation of the blood. 
Very frequently the digestive organs require special medication, when 
such remedies as pepsin, pancreatin, hydrochloric acid, and bismuth 
subnitrate are indicated. 

The following prescriptions have proved to be very excellent in their 
special province. 

As general tonics: 

1$ — Sodii arsenit gr. j 

Ferri sulphat. exsiccat., 

Sodii bicarb aa 5j 

Ft. pilulse No. xx. 

Sig. — One after each meal. 

1$ — Strychninse sulph gr. j 

Acid, hydrochlor. dil §ij 

Infus. gentian, comp. q. s. ad §iij 

Sig. — Teaspoonful in water after each meal. 

In cases of undue hemorrhage after extracting, it is well to administer 
a hemostatic, while at the same time styptics and pressure are being 
applied locally. 

EXTRACTION UNDER THE INFLUENCE OF GENERAL ANESTHETICS 

While it is undoubtedly true that the extraction of teeth under the 
influence of a general anesthetic is in accordance with the general spirit 



USE OF GENERAL AXESTHETICS 611 

of the age which seeks to spare all suffering or cause the infliction 
of but slight pain, vet many evils attend such general and too often 
indiscriminate use. "A patient under the effect of so powerful a drug 
that consciousness is destroyed is nearer death than an ordinary human 
being, since the primary depressive influence upon the high nervous 
centres may speedily pass to the lower vital centres in the medulla 
oblongata." 1 

The indiscriminate use of general anesthetics, besides their possible 
danger to life and health, has an accompanying evil in the demand 
for the extraction of teeth which are salvable and useful, but which 
a patient insists upon having removed in order to avoid the discom- 
fort attendant upon their treatment and filling. No one questions 
or denies the enormous benefit of general anesthetics in dentistry, 
particularly when painful operations are to be performed upon ner- 
vous women and children; but if the patient be willing to suffer a little 
pain it is generally better to extract without a general anesthetic, as in 
that case the patient can assist the operator by keeping the head in 
a desired position with the mouth and lips well open, and in various 
other ways, while under the influence of an anesthetic the muscles 
supporting the head, jaws, and cheeks are so relaxed that it is difficult 
to keep the mouth and lips well open. 

If the operation is to extract a difficult tooth, the operator is limited 
to the time when the patient is under the influence of an anesthetic, and 
in the case of nitrous oxid the time is very short; but without an anes- 
thetic there is not this limitation as to time, and the extraction may be 
done with that care and deliberation essential to a proper operation. It 
is an important rule in any branch of surgery that the time required 
to do an operation must be sufficient to do it properly and without 
unnecessary injury to the adjoining tissues. 

Examination of a Patient before the Administration of a General Anes- 
thetic. — The physical examination should be made in such a way that 
it will not cause alarm to the patient. The result of this examination 
governs the selection of the anesthetic, and to some extent shows how 
far the patient should be carried under its influence. It has been 
said that a greater amount of care should be used if the patient has 
or is suspected of having organic or functional disease of either the 
heart or the lungs. This is quite true; but at the same time the greatest 
amount of care should be observed in all cases. 

The question often arises whether anesthetics should be used at all 
if the patient has either organic or functional disorder of the heart. 
That depends to a large degree on other conditions of the patient. If 
the shock of extraction will be less under ether or nitrous oxid, then bv 
all means the anesthetic should be given and the patient carried well 

1 H. A. Hare, Park's Text-book of Surgery, vol. ii. 



612 EXTRACTION OF TEETH 

under its influence, so that there will be neither pain nor knowledge of 
the operation. Occasionally patients suffering from heart disorders 
can bear a certain amount of pain without shock; in such cases it is 
better, if the operation be a simple one, to extract while in the normal 
condition. 

It is also true that an individual may show on examination evidences 
of considerable organic defect of the heart without running any more 
risk than a person who shows no such signs. For example, a loud 
systolic murmur may be heard at the apex of the heart, a sign of mitral 
regurgitation, and at the same time the patient will be in the best of health 
as far as functional activity of the heart is concerned. Therefore the 
presence of a cardiac murmur in itself is no contraindication to the use 
of an anesthetic, but if the patient shows signs of poor compensation, 
I. e., marked dyspnea, cough, edema of the feet, or irregularity of cardiac 
action, extreme caution should be employed. 

These remarks apply to anesthesia for the shortest dental operation 
whatever the anesthetic. In longer operations such as extraction of 
impacted teeth, when the anesthesia must be complete and kept up for 
some time, thorough examination of the lungs and kidneys should also 
be made. Pulmonary tuberculosis and chronic bronchitis are contra- 
indications to ether anesthesia. In testing the function of the kidneys, 
the quantity of urine excreted in twenty-four hours as well as the presence 
of albumin or casts should be noted. Ether is a powerful irritant to the 
kidneys, albumin and casts appearing in the urine after its adminis- 
tration in a great number of cases in which they were previously absent. 
This action of ether must therefore be borne in mind in its adminis- 
tration. 

Ether is a much safer anesthetic than chloroform. Statistics from 
various sources show the death rate from ether to be about 1 in 16,000, 
and from chloroform 1 in 4000, a proportion of 1 to 4. 

Chloroform, therefore, should not be used except under very exceptional 
circumstances and never for the short operations here under consideration. 
Many writers recommend its use especially in children rather than 
ether, but there is no evidence to show that it is more suitable for them 
than for adults. It has been truly said by one of our leading teachers, 
"There is no use in a dental surgery for chloroform except to dissolve 
gutta-percha." 

The disagreeable effects of anesthetics can to a great extent be avoided 
by proper preparation of the patient. In all long operations the patient 
should take a laxative in the evening, followed on the morning of oper- 
ation by an enema of soap and water. The patient should eat no break- 
fast on the day of operation, which is therefore best performed in the 
morning. 

Before the operation the patient should be asked to empty the bladder 
and bowels if possible, the clothing should be loosened about the neck, 



USE OF GENERAL ANESTHETICS 



613 



and all removable artificial dentures should be taken from the mouth. 
and a mouth prop placed in position. 

The ordinary dental chair is not well suited to operating under general 
anesthetics. In nitrous oxid anesthesia, the body assumes a position 
of hvperextension and the foot rest or other parts of the dental chair 
may be broken by the force of the muscular contraction. If a dental 
chair must be used, the 
foot-rest should be lowered 
out of reach of the patient's 
feet before giving the anes- 
thetic, and a detached stool 
placed beneath the feet. 
For longer operations, the 
patient should be placed 
in a recumbent or semi- 
recumbent position. 

The use of ether for ex- 
tracting has certain advan- 
tages. If for any reason 
the operation requires 
longer time for its per- 
formance than the influence 
of the nitrous oxid will last 
— say from one to two 
minutes — it is better to 
use ether. Ether can be 
given after the patient has 
become anesthetized by 
nitrous oxid and oxygen, 
and he may be kept under 
its influence for a consider- 
able time; in this way the 
struggling stage of ether 
may be avoided. When 
the teeth are to be ex- 
tracted at the patient's 
home or at any other place 
outside of an operating 
room, ether is more con- 
veniently carried than nitrous oxid. If properly used and the patient 
has perfect confidence in the operator, ether can be so administered that 
one. two. or three teeth may be extracted during what is known as the 
first stage of ether anesthesia, before complete unconsciousness and long 
before the struggling stage commences. 

The best way to accomplish this is to administer the ether in a cone made 




Nitrous oxid gasometer. 



614 



EXTRACTIOX OF TEETH 



by a napkin or towel, with the small end slightly opened so as to allow the 
patient to inhale a sufficient quantity of air; it also permits the patient 
to exhale freely and with a less suffocating effect. It is well to place in 
the cone a small soft sponge that has been well washed with hot water. 
After the cone is ready the patient should be instructed to breathe 
several long and full inhalations; this clears the lungs of much impure 



Fig. 666 



— - —Water line 




gas cylinder 



Sectional view of gasometer. 



air and accustoms the patient to the kind of breathing required. Then 
the appliance is placed at a short distance above the mouth and nose so 
that the vapor will gravitate to them, being careful to allow none of the 
ether to drop from the cone upon the face, as it would demoralize the 
patient. The inhaler is to be advanced toward the face slowly and 
gradually, watching the effect upon the patient; if there is a tendency 



USE OF GENERAL ANESTHETICS 615 

to cough, the advance should be interrupted until this has passed. After 
the cone has closed tightly over the mouth and nose, it is a good plan 

Fig. 667 




Nitrous oxid inhaler. 



to ask the patient to hold up the left hand as long as possible; this will 
concentrate his thoughts upon the act and away from the operation. 
When the hand begins to fall, the request to raise the hand should be 



616 



EXTRACTION OF TEETH 



repeated; it will soon fall, and in a few seconds afterward, one, two, or 
three teeth may be removed, the number depending entirely upon their 
position and the difficulty to be overcome in their extraction. As soon as 



Fig. 668 




Hood inhaler. 



the teeth are extracted the head of the patient should be raised from the 
head-rest and the body carried forward, and, having a hand cuspidor 
in front, the patient should be requested to eject the blood from the 
mouth; this direction is usually complied with. The patient in most 



USE OF GENERAL ANESTHETICS 



61' 



instances recovers in a few moments, and with no disagreeable after- 
effects; but if the ether is carried beyond the struggling stage to the 



Fig. 669 




Stand for compressed gas cylinder, gas bag, tube, and inhale 



618 



EXTRACTION OF TEETH 



point of complete surgical narcosis the nauseating after-effects are very 
disagreeable unless the patient has been thoroughly prepared for the 
occasion. 

Nitrous oxid is the anesthetic most commonly administered for the 
extraction of teeth, and under ordinary circumstances is the best. Until 
lately every operator was his own maker of the gas— this was a great 
disadvantage— but now it can be procured in a liquefied form com- 
pressed in cylinders. There are many different appliances used for 
the administering of this gas even when using it in a condensed form. 
One of the most prominent is that shown in Figs. 665 and 666, in which 
the gas is drawn into a reservoir and then passes through a flexible 
tube to the mouth-piece (Figs. 667 and 668). 



Fig. 670 




Portable nitrous oxid apparatus. 

The two principal mouth-pieces are Fig. 667, which should have 
the detachable lip-shield removed so that the tube may be placed 
directly into the mouth and the lips compressed around the tube by the 
operator, at the same time closing the nostril by the thumb and finger, 
and Fig. 668, which is known as a hood inhaler; it is made to cover 
the nose as well as the mouth. The advantage of the first mouth- 
piece is that the lips may be closely watched for the change of color 
denoting oxygen starvation of the blood, which the experienced oper- 
ator combats by admitting a certain amount of air with the gas as 



USE OF GENERAL ANESTHETICS 619 

required. This advantage can be given to the hood inhaler shown in 
Fig. 668 by having it made of transparent material, such as celluloid. 
Fig. 670 represents a portable appliance to be used at a patient's home 
or away from the regular office. 

Hewitt's Method. — Sir Frederic Hewitt, of London, England, has 
devised the apparatus shown in Figs. 671 and 672. The three cylinders 
contain the compressed gas, two being filled with nitrous oxid and 
one with oxygen. The valves of the cylinders are opened by a key 
which is controlled by the foot of the operator. The tube passing from 
the cylinders to the receiving bag is double, a smaller tube being placed 
within the outer larger tube. The receiving bag is also double, being- 
divided by a rubber septum into two compartments which have their 
outlet in the double tube which leads to the inhaler. To the receiving 
bag is attached a mixing chamber, and to this the inhaling tube or hood 
is fastened. This appliance is used very successfully in England and 
has been introduced into the United States. It has proved satisfactory 
to all who have tried it. The bags and tubing should be made of more 
durable material when intended for use in the American climate. 

The manner in which the appliance is used is as follows: The valves 
in the mixing-chamber (Fig. 672) are closed, then oxygen is let into its 
compartment of the receiving bag until the latter is nearly filled, when 
the nitrous oxid is admitted into its compartment. The patient being- 
prepared, the inhaling tube or hood is placed in position, and the patient 
is directed to breathe — long, full, and steadily. If the tube is used it 
is necessary to close the nose by the thumb and finger. 

The valves are not changed for a few inhalations, during which time 
only air is inhaled; then, pressing the indicator a downward to the first 
notch b, the air is cut off, and the patient receives pure nitrous oxid; 
this is allowed for a few more inhalations, and then the indicator is 
carried to the next notch and one part of oxygen is allowed to pass into 
the respiration. When the indicator is carried to the third notch two 
parts are received by the patient, and so on until the maximum amount 
of oxygen required by the patient has been reached. 

It has been found by careful study of many thousands of cases and 
by special scientific investigation that the asphyxial condition incident 
to most cases of nitrous oxid inhalation is quite unnecessary to the pro- 
duction of nitrous oxid anesthesia. It is also justly considered to be 
subjecting a patient to an unwarrantable danger to permit the asphyxial 
effect to manifest itself to a profound degree, as in many cases it is 
a menace to life and health, and might have a fatal effect. The object 
of Dr. Hewitt's method is to control or eliminate the asphyxial element 
by administering a requisite amount of oxygen. 

Xo fixed rule can be laid down for the quantity of oxygen to be added, 
as each case will require a different amount, and this amount varies 
during the several stages of the anesthetic procedure. The operator 



620 



EXTRACTION OF TEETH 

Fig. 671 




Complete apparatus of Dr. Hewitt for administering mixed nitrous oxid and oxygen. 

Fig. 672 




Showing arrangement of the mixing chamber, with dial and valve for 
relative proportions of the gases. 



controlling the 



USE OF GENERAL ANESTHETICS 



621 



is guided entirely by the symptoms of the patient during the adminis- 
tration, his object being to avoid on the one hand the tendency toward 



Fig. 673 




Apparatus for administering nitrous oxid and oxygen combined: a, key to oxygen bag; 6, key to 
oxygen cylinder; c, gauge showing percentage of oxygen being administered; d, mixing chamber; 
c, c, keys to nitrous oxid cylinders; /, key to nitrous oxid bag. 



622 EXTRACTION OF TEETH 

asphyxia indicated by cyanosis of the lips, and return of consciousness 
and sensation on the other hand, which is easily produced by an excess 
of oxygen. By the admixture of oxygen, as in Dr. Hewitt's method, 
the anesthesia is somewhat prolonged over the ordinary nitrous oxid 
method and is slower of induction ; but there is entire absence of cyanosis, 
stertorous breathing, jactitation, or any of the symptoms of asphyxia. 
The modification of the Hewitt apparatus that has been lately intro- 
duced embodies certain features that make it an improvement on the 
original apparatus. The arrangement of the mixing-chamber in reference 
to the bags containing the gases is such as to enable the operator to more 
accurately control the mixture that is administered to the patient. By 
a turn of the levers a and / (Fig. 672) any gradation of the gases may 
be obtained, from pure nitrous oxid on the one hand, to pure oxygen on 
the other. The construction of the apparatus is such as to better with- 
stand the climatic conditions than the Hewitt apparatus. A brief 
description will suffice to show the working of the apparatus. 

There are three cylinders, two containing compressed nitrous oxid, 
and the other compressed oxygen. 

Two bags, one of black material to contain the nitrous oxid, the 
other of red material to contain the oxygen. 

The key to each cylinder (see b and e, e) opens the valve and allows 
the gas to pass into its respective bag. 

By opening the valve (see /) of the nitrous oxid bag the gas passes 
into the mixing chamber, from which it flows through the covered 
rubber tube to the inhaler. 

When it is desired to combine oxygen with nitrous oxid, open gauged 
valve (see a, c) to the oxygen bag; this will admit the oxygen into the 
mixing chamber. Both gases will pass through the tube to the inhaler. 

The proportion of oxygen used will be determined by the degree to 
which the gauged valve is opened. 

By closing the valve of the nitrous oxid bag, oxygen can be given 
separately. 

Similar results are obtained when air is admitted, instead of oxygen, 
to the patient during the nitrous oxid administration. 



CHAPTER XVIII 
LOCAL ANESTHESIA 

By HERMANN PRINZ, M.D., D.D.S. 

Local anesthetics are agents which are employed for the purpose of 
producing insensibility to pain in a circumscribed area of tissue. 

History. — From an historical viewpoint, comparatively few important 
factors are to be recorded prior to the introduction of cocain for the pur- 
pose of locally obtunding pain. The compression of nerve trunks for the 
abolition of pain seems to be of an old and unknown origin, which was 
revived by Guy du Chauliac and Ambroise Pare, and indirectly found 
a permanent place in surgery as the Esmarch elastic bandage. Physi- 
cally reducing the temperature of a part of the body by the application 
of cold was instituted much later. Bartholin and Severino introduced 
this method in the middle of the Sixteenth century. It became a lost art, 
however, until John Hunter, of London, again called attention to its 
benefits by demonstrating it upon animals, and Larrey, the chief surgeon 
of Napoleon's army, employed it for amputating purposes (1807). 
Through the efforts of Sir B. W. Richardson, in 1866, it was placed 
upon a rational basis by the introduction of the ether spray. The various 
narcotics which were employed for internal purposes were also made 
use of as local applications. Mandragora, henbane, aconite, the juice 
of the poppy-head, and many other analgesic drugs enjoyed a world- 
wide reputation. The empirical search for new methods and means 
pressed the mysticism of the electric current into service, opening a 
prolific field to the charlatan which even to this day has not lost its 
charm. Richardson's voltaic narcotism for a time attracted the atten- 
tion of the medical profession; and Francis, in 1858, recommended the 
attachment of the electric current to the forceps for the painless extrac- 
tion of the teeth, and as dental depots still offer appliances of this nature 
for sale, it seems that the method is still in vogue with some operators. 
In the early days of modern dentistry we meet with many feeble efforts 
to alleviate pain during trying operations. Chloroform, alcohol, ether, 
aconite, opium, the essential oils, and many other drugs were the usual 
means employed, either simply or as compounds, usually under fanciful 
names, for such purposes. Snape's calorific fluid, composed of chloro- 
form, tincture of lemon balm, and oil of cloves; nabalus, consisting of 
glycerite of tannic acid and a small quantity of chloral hydrate; Morton's 
letheon, w T hich was sulphuric ether mixed with aromatic oils, are 

(623) 



624 LOCAL ANESTHESIA 

examples of proprietary preparations which enjoyed quite a reputation 
in their time. 

In 1853 Alexander Wood introduced a method of general medication 
by means of hypodermic injections. At once it was suggested to employ 
such drugs as morphin or tincture of opium for the purpose of pro- 
ducing local anesthesia. The results were not encouraging, however, 
until Koller, in 1884, advocated cocain. With the introduction of this 
drug into therapeutics, local anesthesia achieved results which were 
beyond expectations, and its adoption created a new era in local anes- 
thesia. 

Means of Producing Local Anesthesia. — The term anesthesia (without 
sensation), which was suggested in 1846 by that great physician- 
literateur, Oliver Wendell Holmes, to Dr. Morton, is usually defined 
as an artificial deprivation of all sensation, while the mere absence 
of pain is referred to as analgesia. Correctly speaking, the term local 
anesthesia is partially a misnomer. In producing local anesthesia we 
do not fully comply with all the requirements that anesthesia demands, 
because a part of the sensorium — the sense of touch, for instance — is not 
abolished. The term local anesthesia has, however, acquired such 
universal recognition that it would seem unwise to recommend a change. 

Anesthesia may be artificially produced by inhibiting the sensory 
nerve fibers at their central end-organs in the brain or at their peripheral 
end-organs in the tissues, thus producing general and local anesthesia. 
Local anesthesia may be obtained in two definite ways. We may 
inhibit the function of the peripheral nerves in a circumscribed area of 
tissue, and we refer to this process as "terminal anesthesia," while if 
we block the conductivity of a sensory nerve trunk somewhere between 
the brain and the periphery we speak of it as "conductive anesthesia." 
Conductive anesthesia may be produced by injecting into the nerve 
trunk proper — endoneural injection — or by injecting into the tissues 
surrounding a nerve trunk — perineural injection. The latter form is 
the usual method pursued when conductive anesthesia for dental pur- 
poses is indicated. Specific forms of local anesthesia may also be pro- 
duced by paralyzing the sensory ganglia in the brain or in the spinal 
cord; these methods have, however, no bearing on the subject under 
consideration. 

The successful practice of local anesthesia involves the careful 
coordination of a number of important details, each one constituting a 
definite factor in itself, which, when neglected, must necessarily result 
in failure. As a whole, the practice of local anesthesia by the hypo- 
dermic method represents a composite of the following factors: 

1. A solution of active ingredients in accord with the physical and 
physiological laws which govern certain functions of the living cell. 

2. A carefully selected hypodermic armamentarium. 

3. A complete mastery of the technique. 



PHYSIOLOGICAL ACTION OF ANESTHETICS 625 

4. A proper selection of the correct method suitable for the case at 
hand. 

5. Good judgment of prevailing conditions. 

Physiological Action of Anesthetics. — According to more recent thera- 
peutic conception, it is generally recognized that a drug or a combina- 
tion of drugs which simultaneously produce local anemia and inhibition 
of the sensory nerves in a circumscribed area of tissue is the logical 
solution of the question of local anesthesia. Certain important factors, 
however, relative to the physiological and physical action of the solution 
employed for hypodermic injection upon the cell, govern the successful 
application of such methods. It is of prime importance, therefore, to 
comply with the laws regulating the absorption of injected solution, viz., 
osmotic pressure. 

If we separate two solutions of salt of different concentration by a per- 
meable membrane, a continuous current of salt and water through the 
membrane results, which ceases only after equalization of the density of 
the two liquids, viz., when equal osmotic pressure — according to the 
Boyle- Van't Hoff's law — is established. The current passes in both 
directions, drawing salt from the stronger to the weaker solution and 
water, vice versa, until osmotic equilibrium is obtained. The resultant 
solutions are termed isotonic (De Vries). Osmotic pressure is a physical 
phenomenon which is possessed by water and all aqueous solutions; it is 
dependent upon the number of molecules of salt present in the solution 
and upon their power of dissociation. In organized nature these osmotic 
interchanges are an important factor in regulating the tissue fluids of 
both animals and plants. In the animal tissue the circulation depends 
principally upon the mechanical force exerted by the heart. The life 
of the cell depends upon the continuous passage of the fluids which 
furnish the nutrient materials, consisting of water, salt, and albumin. 
These chemicals are normally present in certain definite proportions. 
The membrane of the living cell is, however, only semipermeable, viz., 
the cell readily absorbs distilled water when surrounded therewith; it 
becomes macerated, loses its normal structure, and finally dies. If, on 
the other hand, the surrounding fluid be a highly concentrated salt 
solution, the solution absorbs water from the cell; no salt molecules enter 
the cell body proper. The cell shrinks and finally dies. This process of 
cell death is in general pathology referred to as necrobiosis. 

A further important factor teaches us that all aqueous solutions which 
are isotonic possess the same freezing point, viz., all solutions possessing 
an equal freezing point are equimolecular; they possess equal osmotic 
pressure. This law of physical chemistry has materially simplified the 
preparation of such solutions. The freezing point of human blood, 
lymph serum, etc., has been found to equal, approximately, 0.55° C, 
which in turn corresponds to a 0.9 per cent, sodium chlorid solution. 
Such a solution is termed a physiological salt solution. In the older 
40 



62G LOCAL ANESTHESIA 

works on physiology a 0.6 per cent, sodium chloric! solution is referred 
to as a physiological salt solution; this solution corresponds to the 
density of the blood of a frog. A slight deviation above and below the 
normal percentage of the solid constituents is permissible. When 
physiological salt solution at body temperature is injected into the loose 
connective tissue under the skin in moderate quantities, neither swelling 
nor shrinkage of the cells as such occurs; a simple wheal is formed which 
soon disappears, therefore no irritation results, and in consequence no 
pain is felt. Other similar bodies which are equally soluble in water act in 
the same manner, with the exception of the salts of the alkali and earth 
metals, such as potassium or sodium bromid, for example. The latter 
substances produce intense physical irritation, followed, however, by 
prolonged anesthesia, and in consequence are termed by Liebreich "pain- 
ful anesthetics." If, on the other hand, simple distilled water be injected, 
a superficial anesthesia only is produced; the injection itself is very 
painful and acts as a direct protoplasm poison by macerating the cell 
contents and resulting in severe damage or even death of the cell. If 
distilled water approximately at the ratio of 10 drams to the pound of 
body weight be injected into dogs, they will succumb in a short time. 
The injection of higher concentrated salt solution produces opposite 
effects; water is removed from the cells with more or less pronounced 
pain, also followed by superficial anesthesia. The red corpuscles are 
extremely susceptible to any injected fluid which is not isotonic in its 
nature. They are universally destroyed (hemolysis) by the injection of 
fluids which are not represented by an isotonic salt solution. Hypotonic 
solutions, then, cause swelling of the tissue, while hypertonic solutions 
produce shrinkage. These manifestations are proportionately the more 
intense the further the solution is removed from the freezing point of 
the blood. Furthermore, hypotonic solutions as well as hypertonic 
solutions require much more time for their absorption than isotonic 
solutions; the osmotic pressure has to be standardized to the surrounding 
fluid, viz., to the isotonic index of the tissue fluids. Local anemia or 
ischemia, viz., a temporary constriction of circulation — presents, as has 
been experimentally shown, the rapid absorption of fluids which are 
injected into the affected area. 

The more important means to produce local anemia are: (1) The 
Esmarch elastic bandage. (2) The application of cold. (3) The extract 
of the suprarenal capsule. 

Some observers have maintained that local anemia produces anes- 
thesia. This is not, however, the case; it is merely an important means 
to confine the injected anesthetic to the anemic region, and thus bring 
about an increased and prolonged action of the drug. Consequently, 
the concentration of the anesthetic solution may be of a lower percentage, 
which, of course, lessens the danger of intoxication. For plausible reasons 
the Esmarch elastic bandage cannot be made of use for dental operations. 



ETHYL CHLORID AND ITS ADMINISTRATION 627 

Physically reducing the temperature of the body by the application 
of cold (ice pack, ice and salt mixture, cold metals, etc.) was practised 
by the older surgeons. Arnott in 1849 and Blundell in 1855 advocated 
ice packs for the painless extraction of teeth. Through the efforts of Sir 
B. W. Richardson, in 1866, this method was placed on a rational basis 
by the introduction of his ether spray. To obtain good results, a pure 
ether (boiling point 95° F., 35° C.) free from water is necessary. Certain 
volatile hydrocarbons possess similar properties in varying degrees, 
depending on their individual boiling point. In 1867 Rottenstein called 
attention to the use of ethyl chlorid as a refrigerating agent, and Rhein, 
in 1889, introduced methyl chlorid for the same purpose. In 1891 
Redard reintroduced ethyl chlorid as a local anesthetic, which since has 
become known by many trade names — as antidolorine, kelene, narcotile, 
etc. — and mixtures of the first two in various proportions known as 
anestol, anestile, coryl, metethyl, etc., are extensively used in minor, 
oral, and general surgery. A pure ethyl chlorid (boiling point 55° F., 
13° C.) is best suited for this purpose, as it lowers the temperature of 
the tissues sufficiently to produce a short superficial anesthesia in a few 
minutes. Too rapid cooling or prolonged freezing by methyl chlorid 
(boiling point, 12° F., 24.5° C.) or the various mixtures thereof, produce 
deeper anesthesia, but such procedures are dangerous. They frequently 
cut off circulation in the affected part so completely as to produce 
sloughing (gangrene). Liquid nitrous oxid, liquid or solid carbonic 
acid (recently known as carbonic acid snow), and liquid air, all of 
which have a boiling point far below zero, are recommended for similar 
purposes, but they require cumbersome apparatus and are extremely 
dangerous. 

ETHYL CHLORID AND ITS ADMINISTRATION 

Ethyl Chlorid (Monochlorethane ; Hydrochloric Ether; C 2 H 5 C1).— "A 
haloid derivative, prepared by the action of hydrochloric acid gas on 

Fig. 674 




Ethyl chlorid spray tube. (Metal.) 



absolute alcohol." At normal temperature, ethyl chlorid is a gas, and 
under a pressure of two atmospheres it condenses to a colorless, mobile, 



028 LOCAL ANESTHESIA 

very volatile liquid, having a characteristic, rather agreeable odor, and 
burning taste. It boils at about 55° F. (13° C.) and is very inflammable, 
burning with a smoky, green-edged flame. It is stored in sealed glass 
or metal tubes, and when liberated at ordinary room temperature, 
70° F. (21° C), it evaporates at once. In commerce it is supplied in 
plain or graduated glass tubes of from 3 to 60 grams' capacity, or stored 
in metallic cylinders holding from 60 to 100 grams or more. To remove 
the ethyl chlorid from the hermetically sealed small tubes, the neck has 
to be broken off, while the larger glass and metallic tubes are provided 
with suitable stopcocks of various designs to allow definite amounts of 
the liquid to be released. 

Mode of Application. — For the extraction of teeth, immediate removal 
of the pulp, opening of abscesses, and other minor operations about the 
oral cavity, the tube should be warmed to body temperature by placing 
it in heated water, and its capillary end should be held about six to ten 
inches from the field of operation. The distance depends on the size 
of the orifice of the nozzle, and complete vaporization should always 
be produced. The Gebauer tube is fitted with a spray nozzle, which 
shortens the distance to one to two inches, and is especially well adapted 
for dental purposes. The stream is directed upon the tissues until 
the latter are covered with ice crystals and have turned white. For 
the extraction of teeth, the liquid should be projected directly upon the 
surface of the gum, as near to the apex of the root as possible, but care 
should be taken to protect the crown of the tooth on account of the 
painful action of cold on this part. The tissues to be anesthetized should 
first be dried and well surrounded by a film of vaselin or glycerin, and 
protected by cotton rolls and napkins, to prevent the liquid from running 
into the throat. Let the patient breathe through the nose. Occasionally 
light forms of general anesthesia are induced by inhaling the vapor. 
On account of the difficulty of directing the stream of ethyl chlorid upon 
the tissue in the posterior part of the mouth, it is not successfully applied 
to those regions. The intense pain produced by the extreme cold pro- 
hibits its use in pulpitis and acute pericementitis. To anesthetize the 
second and third branch of the fifth nerve, it is recommended to direct 
the stream of ethyl chlorid upon the cheek in front of the tragus of the 
ear, but the author has not seen any good results from such a procedure. 
Caution should be exercised in using ethyl chlorid near an open flame 
or in conjunction with the thermocautery, as severe burns have resulted 
by setting the inflammable vapor on fire. 

THE ACTIVE PRINCIPLE OF THE SUPRARENAL CAPSULE AND 
ITS SYNTHETIC SUBSTITUTES 

Within the last decade the active principle of the suprarenal capsule 
has evoked extensive comments in therapeutic literature. It has been 



SUPRARENAL CAPSULE AND ITS SYNTHETIC SUBSTITUTES 629 

isolated by a number of investigators under different names, as epine- 
phrin by Abel (1897), suprarenin by Fuerth (1898), and adrenalin by 
Takamine and Aldrich (1901). Many other titles are given to this 
chemical — as adnephrin, adrin, paranephrin, suprarenalin, supra- 
capsulin, hemostasin, etc. The United States Pharmacopoeia (eighth 
revision) has not as yet admitted this alkaloid to its pages, and, therefore, 
whenever we refer here to the hydrochloric salt of the alkaloid of the 
suprarenal capsule, we speak of it as adrenalin, the term which is at 
present preferred in the United States. Adrenalin is a grayish-white 
powder, slightly alkaline in reaction, and perfectly stable in dry form. 
It is sparingly soluble in cold and more soluble in hot water, is insoluble 
in ether or alcohol, and with acids it readily forms soluble salts. The 
preparation that is employed mostly for therapeutic purposes is a solu- 
tion of adrenalin hydrochlorid in a 1 to 1000 physiologic salt solution, 
to which preservatives — as small quantities of chloretone, thymol, etc. — 
are added. Adrenalin solution does not keep well. On exposure to air 
it is easily oxidized, becoming pink, then red, and finally brown, and 
with this change of color its physiologic property is destroyed. If the 
adrenalin solution be further diluted, it becomes practically worthless 
within a few days. 

When adrenalin is injected into the tissues, even in extremely small 
doses, it temporarily raises the arterial blood pressure, acting as a 
powerful vasoconstrictor by stimulating the smooth muscular coat of 
the bloodvessels, and thus produces local anemia. Large doses finally 
reduce the blood pressure, and heart failure results. The respiration 
at first quickly increases, but slows down and finally stops with expira- 
tion. Its action is largely confined to the smooth muscle fibers of the 
peripheral vessels. Adrenalin is destroyed by the living tissue cells, 
the body ridding itself of the poison in some unknown manner. While 
adrenalin does not possess local anesthetic action, it increases very 
markedly the effect of certain anesthetics when combined with them. 
These observations are of vast importance in connection with the 
production of local anesthesia. Carpenter, Peters, Moller, and others 
referred to the use of adrenalin in this respect, and finally Braun, in 1902, 
published his classic researches, and to him and his co-workers, especially 
Heinze and Laewen, belongs the credit of establishing a rational basis 
for the production of local anesthesia. It is claimed that secondary 
hemorrhage frequently occurs after the anemia produced by the adrenalin 
has subsided, and that the tissues themselves suffer from the poisoning 
effect of the drugs, resulting in gangrene. Such results are produced 
only by the injection of too large quantities of the drug, which by their 
deeper action close up the larger arteries. The prolonged anemia will 
give way to a dilatation of the bloodvessels, and, if the tissues are too 
long deprived of the circulation, we are able to understand why sloughing 
may result. Small doses of adrenalin have no effect upon the tissues or 



630 LOCAL ANESTHESIA 

on the healing of a wound. Palpitation of the heart and muscular 
tremor, which were occasionally noticed in the early period of the use 
of the drug, are the direct result of too large doses. Recently a synthetic 
adrenalin has been successfully prepared by Stolz, which, with hydro- 
chloric acid, forms a stable and readily soluble salt. It is known as 
synthetic suprarenin hydrochlorid. The new chemical has been care- 
fully tested physiologically and in clinical work, and the general consensus 
of opinion points to the fact that it is not alone equal, but in certain 
respects superior, to the organo-preparations. Synthetic suprarenin 
solutions may be readily sterilized by boiling. They are relatively 
stable, and their chemical purity insures uniform results. They are com- 
paratively free from dangerous side actions. The writer's observations 
regarding the value of synthetic suprarenin relative to its actions and 
its general behavior is in full accordance with the above statements, 
and its advantages over the organo-preparations has led him to adopt it 
as a component in the preparation of local anesthetic solutions. For 
dental purposes — that is for injecting into the gum tissue — the dose may 
be limited to one drop of the adrenalin solution (1 to 1000) or the syn- 
thetic suprarenin solution (1 to 1000), added to each cubic centimeter 
of the anesthetic solution, 5 drops being approximately the maximum 
dose to be injected at one time. 



THE LOCAL ANESTHETICS 

Cocain. — Cocain, when injected into the tissues, produces typical 
local and general effects. Locally, it possesses a definite affinity for the 
peripheral nerves; it causes constriction of the smaller arteries, producing 
light anemia in the injected area with diminished action of the leukocytes. 
However, different parts of the organism require different doses to bring 
about the same reaction. Upon mucous surfaces, paralysis of the sensory 
nerves is produced; the senses of touch and smell are temporarily in- 
hibited. The blood as such and the circulation suffer little. If cocain 
in sufficient quantities is absorbed by the circulation, general manifesta- 
tions are produced from bringing other tissues in close contact with the 
poison. The principal disturbances of the central nervous system make 
themselves known by vertigo, a very soft pulse, enlarged and staring 
pupils, and difficult respiration. Vomiting may occur; the throat feels 
dry. Intense excitement is followed by epileptiform spasms; finally, 
complete loss of sensation and mobility results, which terminates in 
death from cessation of respiration. The general character of the dis- 
turbances is closely related to that which occurs in chloroform or ether 
poisoning. The typical picture of cocain poisoning is produced when 
the blood flowing through the central nervous system contains a suffi- 
cient quantity of the drug, even for a moment only, which is dangerous 



THE LOCAL ANESTHETICS 631 

to this organ. Xo maximum dose can be positively established. This 
is equally true of chloroform and ether when used for general anesthetic 
purposes. The many cases of so-called idiosyncrasy probably find an 
explanation in the too large doses which formerly were so frequently 
administered. 

With our increased knowledge of the action of cocain upon the tissues 
and a proper technique of the injection, dangerous results are com- 
paratively rare at present. Xo direct antidotes are known ; the treatment 
of general intoxication is purely symptomatic. Anemia of the brain, 
which is of little consequence, may be readily overcome by placing the 
patient in a recumbent position or by complete inversion, if necessary. 
As a powerful dilator of the peripheral vessels the vapors of amyl nitrite 
are exceedingly useful; it is best administered by placing 3 to 5 drops of 
the fluid upon a napkin and holding it before the nostrils for inhalation. 
Flushing of the face and an increase in the frequency of the pulse follows 
almost momentarily. For convenience sake, amyl nitrite may be pro- 
cured in small glass capsules, holding the necessary quantity for one 
inhalation. Xausea may be remedied by administering small doses of 
spirit of peppermint, aromatic spirit of ammonia, or validol. The latter 
is a compound of menthol and valerianic acid and deserves special 
recommendation. To overcome the disturbances of respiration, quickly 
instituted artificial respiration is the alpha and omega of all methods of 
resuscitation; the only drug that has proved to be of value in this 
connection is strychnin in the form of the sulfate or the nitrate, in full 
doses by means of hypodermic injections. 

The relative toxicity of a given quantity of cocain solution depends 
upon the concentration of the solution. Reclus and others have clearly 
demonstrated that a fixed quantity of cocain in a 5 per cent, solution 
is almost equally as poisonous as five times the same quantity in a h 
per cent, solution. From the extensive literature on the subject we are 
safe in fixing the strength of the solution for dental purposes at 1 per 
cent. This quantity of cocain raises the freezing point of distiMed 
water just a little above 0.1° C. To obtain an isotonic solution corre- 
sponding to the freezing point of the blood, 0.8 per cent, of sodium 
chlorid must be added. Having thus prepared a cocain solution 
which is equal to the blood in its osmotic pressure upon the cell wall, 
it is now necessary to aid the slightly vasoconstrictor power of the drug 
by the addition of a moderate quantity of adrenalin, thus increasing the 
confinement of the solution to the injected area by producing a deeper 
anemia, for the twofold purpose — (1) to act as a means of increasing 
the anesthetic effect of cocain, and (2) to lessen its toxicity upon the 
general system by slower absorption. As stated above, 1 drop of adrena- 
lin solution added to 1 c.c. of the isotonic cocain solution is sufficient 
to produce the desired effect. 



632 LOCAL ANESTHESIA 

A suitable solution for dental purposes may be prepared as follows: 

T$— Cocain hydrochloric! 5 grains (0.30 gm.) 

Sodium chloride 4 grains (0.25 gm.) 

Sterile water 1 fluidounce (30.00 c.c.) 

To each syringeful (2 c.c.) add two drops of adrenalin chlorid solution when 
used. 

Ready made cocain solutions can only be sterilized with difficulty; 
they will not keep when frequently exposed to the air. Ready made 
anesthetic solutions as found in the market usually contain preser- 
vatives such as phenol, naphthol, boric acid, iodin, essential oils, alcohol, 
etc., in variable quantities. Some of these solutions have a distinct acid 
reaction. While they may produce a serviceable degree of anesthesia, 
they usually damage the injected tissues sufficiently to retard the normal 
process of wound healing. 

Substitutes for Cocain. — Ever since the introduction of cocain 
into the materia medica for the purpose of producing local anes- 
thesia, quite a number of substitutes have been placed before the pro- 
fession, for which superiority in one respect or another is claimed 
over the original cocain. The more prominent members of this group 
are tropacocain, the eucains, acoin, nirvanin, alypin, stovain, novo- 
cain, and, very recently, quinin and urea hydrochlorid. None of 
these compounds, with the exception of novocain, has proved satis- 
factory for the purpose in view. The classical researches of Braun 
have established certain factors which are essential to the value of a 
local anesthetic. These factors concern their relationship to the tissues 
in regard to their toxicity, irritation, solubility and penetration, and 
to the toleration of adrenalin. 

There is no need to enter here into a discussion of the pharma- 
cological action of the drugs usually classified as local anesthetics. Let 
it suffice to state how the above-mentioned drugs fulfil the demands 
of Braun. Tropacocain is less poisonous, but also less active than 
cocain, and completely destroys the action of adrenalin; the eucains 
partially destroy the adrenalin action, and are, comparatively speaking, 
equally as poisonous as cocain; acoin is irritating to the tissues and more 
poisonous than cocain; nirvanin possesses little anesthetic value; alypin 
and stovain are closely related, producing severe pain when injected, 
which occasionally has resulted in gangrene. 

According to Le Brocq, the toxicity of these chemicals may be ex- 
pressed as follows. 

If the toxicity of cocain is taken as the standard and expressed as 1, 
then that of alypin will represent 1.25; nirvanin, 0.714; stovain, 0.625; 
tropacocain, 0.5; novocain, 0.49; eucain B, 0.414. 

Novocain alone fully corresponds to every, one of the above claims. 
Its toxicity is about two to six times less than cocain ; it does not irritate 
in the slightest degree when injected, consequently no pain is felt from 



THE LOCAL ANESTHETICS 633 

its injection per se; it is soluble in its own weight of water; it will combine 
with adrenalin in any proportion without interfering with the physio- 
logical action of the latter, and it will be readily absorbed by the mucous 
membrane. The studies of Biberfield and Braun brought to light 
another extremely interesting factor concerning the novocain-adrenalin 
combination. Both experimenters, working independently of each 
other, observed that the adrenalin anemia on the one hand, and the 
novocain anesthesia on the other hand were markedly increased in their 
total effects upon the tissues. Consequently, a smaller quantity of this 
most happy combination is required to produce the same therapeutic 
effect as a larger dose of each individual drug alone would produce 
when injected separately. The injection of a solution of the combined 
drugs is precisely confined to the injected area; general effects are there- 
fore rarely produced. 

Novocain. — Novocain is the hydrochloric salt of a synthetically 
prepared alkaloid, the methyl ester of p-aminobenzoic acid. It is a 
white crystalline powder, or colorless needle-shaped crystals, melting 
at 263° F. (156° C). It may be heated to 200° F. (120° C.) without 
decomposition. It dissolves in an equal amount of cold water, the 
solution having a neutral character; in cold alcohol it dissolves in the 
proportion of 1 to 30. Caustic alkalies and alkaline carbonates pre- 
cipitate the free base from the aqueous solution in the form of a colorless 
oil, which soon solidifies. It is incompatible with the alkalies and 
alkaline carbonates, with picric acid and the iodids. Its solutions may 
be sterilized by boiling without decomposition. 

As stated above, the relative toxicity of a given quantity of cocain 
in solution depends upon its concentration; this same peculiarity is not 
shared by novocain. The dose of novocain may be safely fixed at 
one-third of a grain for a single injection. For dental purposes a H 
or a 2 per cent, solution in combination with adrenalin has been injected 
without any ill results. For the purpose of confining the injected novo- 
cain to a given area, the addition of adrenalin in small doses, on account 
of its powerful vasoconstrictor action is well adapted. It is the important 
factor which prevents the ready absorption of both drugs, and conse- 
quently largely nullifies poisonous results. An injection of 10 drops 
of a 2 per cent, solution of novocain labially into the tissue produces 
a diffuse anesthesia lasting approximately twenty minutes; the same 
quantity, with the addition of one drop of adrenalin chlorid solution, 
increases the anesthetic period to over one hour, and localizes the 
effect upon the injected area. 

A suitable solution of novocain for dental purposes may be prepared 
as follows: 

1^— Novocain . 10 grains (0.60 gm.) 

Sodium chlorid 4 grains (0.25 gm.) 

Distilled water 1 fluidounce (30.00 c.c.) 

Boil. 



6134 



LOCAL ANESTHESIA 



To each syringeful (2 c.c.) add 2 drops of adrenalin chlorid solution 
when used. Fischer strongly advocates the following so-called "normal 
anesthetic solution," which, when prepared under strict aseptic pre- 
cautions, and when preserved in amber colored bottles, will keep. 

1^— Novocain 23 grains (1.50 gm.) 

Sodium chlorid 14 grains (0.92 gm.) 

Thymol | grain (0.02 gm.) 

Distilled water .... 3 fluidounces, If fluidrams (100 c.c.) 

Boil. 

To each c.c. add one drop of synthetic suprarenin solution when used. 

A sterile solution may be made extemporaneously by dissolving the 
necessary amount of novocain-adrenalin in tablet form in a given 
quantity of boiled distilled water. A suitable tablet may be prepared as 
follows : 

ly— Novocain J grain (0.022000 gm.) 

Suprarenin hydrochlorid T 4on grain (0.000054 gm.) 

Sodium chlorid i grain (0.008000 gm.) 

One tablet dissolved in 20 minims of sterile water mekes a 2 per cent, solution of 
novocain ready for immediate use. 



Fig. 675 




Dropping bottle. 



Solutions for hypodermic purposes should 
preferably be made fresh when needed. A 
small glass dish and a dropping bottle constitute 
the simple outfit for such work. The dropping 
bottle should hold from 1 to 2 ounces. A suit- 
able one is made by the Whitall-Tatum Co., 
of Philadelphia, and may be bought in the drug 
shops. It should be provided with a dust cap. 
"A groove on one side of the neck of the bottle, 
and a vent on the other connected with two 
grooves in the back of the stopper allow the 
contents to flow out drop by drop. A quarter 
turn of the stopper closes the bottle tightly." 
The water used for making the solution should 
be boiled and filtered distilled water. The hypo- 
dermic solution can be made extemporaneously 
in a few seconds: Place a tablet in a sterile 
glass dish, add 20 minims (1 c.c.) of water, and 
to facilitate the solution, mash the tablet. The 
solution is now ready for immediate use. 



THE HYPODERMIC ARMAMENTARIUM 

A hypodermic syringe that answers all dental purposes equally well 
is an important factor in carrying out the correct technique of the 
injection. The injection into the dense gum tissue requires from 15 
to 50, or even more, pounds of pressure as registered by an interposed 



THE HYPODERMIC ARMAMENTARIUM 



635 



pressure anesthesia 100 or more pounds are 



dynamometer, while in 
frequently applied. 

The selection of a suitable hypodermic syringe is largely a matter 
of choice. All-glass syringes, 1 glass-barrel syringes, and all-metal syringes 
are the usual types found in 
the depots. 

After testing most of the 
dental hypodermic syringes 
offered in the dental depots 
within the last fiye years by 
means of the pressure gauge and 
in clinical work, subjecting the 
syringes to a routine wear and 
tear, the author has found that 
the all-metal syringes of the 
''Imperial" type are to be pre- 
ferred oyer other makes. They 
are usually made of nickel- 
plated brass, which, however, 
is a disadvantage, as the nickel 
readily wears off from the piston, 
and exposes the easily corroded 
brass. The Manhattan all-metal 
platinoid syringe gives the best 
general service, and can be con- 
scientiously recommended. The 
syringe holds 40 minims (2 c.c.) 
is provided with a strong finger 
cross-bar, and is extremely 
simple in construction. The 
piston consists of a plain metal 
rod, without a thickened or 
ground piston-end or packing. 
The piston-rod is sufficiently 
long to allow about 2 inches of 
space between the cross-bar and 
the piston-top. This space is of 
importance, as it allows the last 

drop of the fluid to be expelled Me tai syringe. 

under heavy pressure without 

tiring the fingers. The packing consists of leather washers inserted 
at the screw point, and are quickly removed and replaced if necessary. 2 

1 An all-glass syringe that answers every demand regarding asepsis, durability, 
and perfect construction, is made by Burroughs, Wellcome & Co. 

2 An all-metal syringe has been introduced by Parke, Davis & Co., which is provided 
with the " Schimmel" aseptic needles and a right-angle attachment for the latter. 




636 LOCAL ANESTHESIA 

The hypodermic syringe requires careful attention. It is not necessary 
to sterilize it by boiling after each use, unless it should be contaminated 
with blood or pus. The simple repeated washings with alcohol and 
careful drying is sufficient. The cap is readjusted, and the piston rod 
is covered with a thin film of carbolated vaselin or surgical lubricating 
jelly and placed in position. If the syringe is boiled, all the washers 
must be removed. The syringe is best kept in a covered glass or 
metal case ; a large bacteriological Petri dish is suitable for this purpose. 
Leather-lined or felt-lined boxes afford breeding places for bacteria, 
and should not be used. Some operators prefer to keep their syringes 
constantly in an antiseptic solution when not in use, and others prefer 
to place them in a special sterilizing bottle, which bottles may now be 
purchased at dental depots. 

Dental hypodermic needles should be made preferably of seamless 
steel, or, still better, of nickel-steel, 26 to 28 B. & S. gauge, and provided 
with a short razor edge point. Thicker needles cause unnecessary pain, 
and thinner needles are liable to break. Iridioplatinum needles are 
preferred by some operators, as they may be readily sterilized in an 
open flame. The needle should measure from a quarter to a half-inch. 
For infiltration anesthesia one inch needles are necessary, and curved 
needles of various shapes are essential in reaching the posterior parts 
of the mouth. The "Schimmel" needles are excellent, but do not, 
however, fit every syringe. For pressure anesthesia special needles 
are required, and may be bought at the depots, or quickly prepared 
by grinding off the steel needle at its point of reinforcement. The 
sterile needle should be kept in well-protected glass containers. The 
needles are sterilized after each use by boiling in plain water, dried with 
the hot air syringe, and immediately transferred to a covered sterile 
glass dish. The sterile needles should not be again touched with the 
fingers, and the customary wire insertion is unnecessary. 



TECHNIQUE OF INJECTION 

Various methods of injecting the anesthetic solution about the teeth 
are in vogue. For the sake of convenience we may divide them as 
follows : 

The subperiosteal injection. 

The peridental injection. 

The intraosseous injection. 

The perineurial injection. 

The injection into the pulp. 
Before starting any surgical interference in the mouth, the field of 
operation should be thoroughly cleansed with an antiseptic solution. A 
thin coat of the official tincture of iodin painted over the surface is very 



TECHNIQUE OF INJECTION . 637 

useful for this purpose. After the diagnosis is made the method of injec- 
tion best suited for the case on hand is then decided. The necessary 
quantity and the concentration of the anesthetic solution is now prepared, 
and the syringe and hypodermic needle fitted ready for the work. To 
facilitate the ready penetration of the needle into the tissues, its point 
may be coated with carbolated vaselin. The correct position of the 
syringe in the hands of the operator and its proper manipulation is an 
important factor, and has to be acquired by practice. The hand holding 
the syringe is exclusively governed in its movement by the wrist, so as 
to allow delicate and steady movements, and the fingers must be trained 
to a highly developed sense of touch. The syringe is filled by drawing 
the solution up into it; it is held perpendicularly, point upward, and the 
piston is pushed until the first drop appears at the needle point, which 
precaution prevents the injection of air into the tissue. 

The Subperiosteal Injection. — The subperiosteal injection about the 
root of an anterior tooth is best started by inserting the needle midway 
between the gingival margin and the approximate location of the apex. 
The pain of the first puncture may be obviated by a fine, very sharp- 
pointed needle, the simple compression of the gum tissue with the finger- 
tip, by holding a pledget of cotton saturated with the prepared anes- 
thetic solution on the gum tissue for a few moments, or by applying a 
very small drop of liquid phenol on the point of puncture. The needle 
opening faces the bone, the syringe is held in the right hand at an acute 
angle with the long axis of the tooth, while the left hand holds the lip 
and cheek out of the way. After puncturing the mucosa, a drop of the 
liquid is at once deposited in the tissue, and the further injection is 
painless. Slowly and steadily the needle is forced through the gum 
tissue and periosteum along the alveolar bone toward the apex of the 
tooth, depositing the fluid under pressure close to the bone on its upward 
and return trip. The continuous slow moving of the needle prevents 
injecting into a vein. A second injection may be made by partially 
withdrawing the needle from the puncture and swinging the syringe 
anteriorly or posteriorly, as the case may be, from the first route of 
the injection. This latter method is especially indicated in injecting the 
upper molars. After removing the needle, place the finger tip over the 
puncture and slightly massage the injected area. A circular elevation 
outlines the injected field. The naturally pink color of the gum will 
shortly change to a white anemic hue, indicating the physiological 
action of the adrenalin on the circulation. No wheal should be raised 
by the fluid, as that would indicate superficial infiltration and conse- 
quently failure of the anesthetic. 

As the liquid requires a definite length of time to pass through the 
bone lamina and to reach the nerves of the peridental membrane and 
the pulp, from five to ten minutes should be allowed before the extrac- 
tion is started. The length of time depends on the density of the sur- 



638 LOCAL ANESTHESIA 

rounding structure of the tooth. The progress of the anesthesia may 
be tested with a fine pointed probe, and its completeness indicates the 
time when the extraction should be started. 

The upper eight anterior teeth usually require a labial injection only, 
while the molars require both a buccal and a palatal injection, using 
a slightly curved needle for this purpose. Buccally the injection is made 
midway between the mesial and distal root, and on the palatal side 
over the palatal root. 

The lower eight anterior teeth are comparatively easily reached by the 
injection. The straight needle is inserted near the apex of the tooth, 
the syringe is held in a more horizontal position, and the injection pro- 
ceeds now as outlined above. 

The lower molars require a buccal and lingual injection. The curved 
needle is inserted midway between the roots, the gum margin, and the 
apices. The external and internal oblique lines materially hinder the 
ready penetration of the injected fluid, and therefore ample time should 
be allowed for its absorption. 

If two or more adjacent teeth are to be removed, the injection by 
means of infiltrating the area near the gum fold directly over the apices 
of the teeth is to be preferred. It is advisable to use a one inch needle 
for this purpose, holding the syringe in a horizontal position, so as to 
reach a larger field with a single injection. 

The injection into inflamed tissue, into an abscess, and into phleg- 
monous infiltration about the teeth is to be avoided. The injection 
into engorged tissue is very painful; the dilated vessels quickly absorb 
cocain without producing a complete anesthesia, and general poisoning 
may be the result. In purulent conditions the injection is decidedly 
dangerous, as it forces the injection beyond the line of demarcation. If 
the abscess presents a definite outline, the injection has to be made into 
the sound tissue surrounding the focus of infiltration. If a tooth is 
affected with acute diffuse or purulent pericementitis, a distal and a 
mesial injection usually produce successful anesthesia by blocking the 
sensory nerve fibers in all directions. 

Peridental Anesthesia. — Teeth or roots standing singly, or teeth affected 
by pyorrhea or similar chronic peridental disturbances, are frequently 
quickly and satisfactorily anesthetized by injecting the fluid directly 
into the peridental membrane. This method is known as peridental 
anesthesia, and its ' technique is very simple. In single-rooted teeth 
a fine and short hypodermic needle is inserted under the free margin of 
the gum, or through the interdental papilla, into the peridental membrane 
between the tooth and the alveolar wall. Sometimes the needle may 
be forced through the thin alveolar bone so as to reach the peridental 
membrane direct. To gain access to this membrane in teeth set close 
together, slight separation with an orange-wood stick or other suitable 
means is often found to be of advantage. Two and sometimes three 



TECHNIQUE OF INJECTION 639 

injections are necessary. To force the liquid into the membrane usually 
requires a higher pressure than that which is necessary for injecting 
into the periosteum covering the alveolar process, but the quantity of 
the anesthetic liquid is less than that which is required for the former 
injection. Acute inflammatory conditions of the peridental membrane 
and its sequelae prohibit the use of this method. Peridental anesthesia 
is the purest form of local anesthesia, since the seat of the nerve supply 
of the tooth is very quickly reached, and as a consequence the results 
obtained are in the majority of cases extremely satisfactory, provided 
that general conditions justify its application. 

Intraosseous Injection. — To facilitate the passage of the injected fluid 
into the bone structure proper, Otte, in 1896, recommended a method 
by which he forces the anesthetic solution directly into the spongy 
cancelloid bone. Otte terms this procedure the intraosseous method of 
injection, and its technique is described by him as follows: After the 
gum tissue is thoroughly cleansed with an antiseptic solution, it is anes- 
thetized about the neck of the tooth in the usual manner. After waiting 
two or three minutes, an opening is made into the gum tissue and the 
bone on the buccal side with a fine spear drill or a Gates-Glidden drill. 
The opening should be made more or less at a right angle with the long 
axis of the tooth, a little below the apical foramen in single-rooted teeth 
or between the bifurcation in the molars. The right-angle hand-piece 
is preferably employed for this purpose. The drill should be of the 
same diameter as the hypodermic needle. The gum fold is tightly 
stretched to avoid laceration from the rapidly revolving drill. As soon 
as the alveolar process is penetrated, a peculiar sensation conveyed 
to the guiding hand indicates that the alveolus proper is reached, and 
the sensation felt by the hand is about the same as that experienced when 
a burr enters into the pulp chamber. In this artificial canal the close- 
fitting curved needle of the hypodermic syringe is now inserted, and the 
injection is made in the ordinary way. The quantity of fluid used is 
much less than is usually needed for a subperiosteal injection. The 
roots of the teeth are embedded in a sieve-like mass of bone tissue (diploe), 
which allows a ready penetration of fluid when injected under pressure. 
Very recentlv, Atasselink, advocates this method for the anesthetization 
of any tooth in the mouth either for the purpose of extraction or the 
removal of its pulp. He employs a No. 4- round bur for penetrating 
the alveolar plate and a very short needle (about one-sixteenth of an 
inch) with a dull point for the injection. 

Perineurial Injection. — For the anesthetization of a number of teeth 
in the upper or the lower jaw, conductive anesthesia by means of peri- 
neurial injection is preferably employed. The perineurial injection is 
made near the point of exit or entrance of the various nerves about their 
respective foramina. To anesthetize all the teeth of one-half of the 
upper jaw four injections are necessary, i. e., two bucally and two on 



640 LOCAL ANESTHESIA 

the palatal side of the bone. A one-inch needle is required for such 
work. To reach the many small branches of the posterior dental nerves 
at the alveolar foramina, the injection is made buccally over the region 
of the tuberosity about \ inch above the gingival line between the first 
and second molar tooth. The second injection is made below the 
infraorbital foramen, so as to reach the middle and anterior dental 
nerves. With the index finger of the left hand the foramen is approx- 
imately located by exerting pressure upon the nerve-exit. The lip is 
lifted up with the middle finger of the same hand and the needle is now 
inserted between the apices of the cuspid and first bicuspid teeth. The 
needle is slowly pushed forward until its point is felt beneath the finger 
tip. To reach the nerve supply of the hard palate one injection is made 
near the posterior palatine canal, and the other near the foramina of 
Scarpa. The great palatine nerves pass through the posterior palatine 
canals on either side of the hard palate. The canals lie about three- 
eighths of an inch above the edge of the alveolar process and the last 
molar tooth. They move posteriorly with the eruption of the successive 
teeth. The nasopalatine nerves pass through the foramina of Scarpa 
(incisive foramen), which are situated in the line of the suture of the 
maxillary bones. If an imaginary line be drawn from the distal borders 
of the two cuspids and passing over the hard palate, the line will ordin- 
arily pass through the foramina. The needle should be inserted directly 
back of the papilla, which lies posteriorly between the central incisor 
teeth. 

To anesthetize one-half of the mandible, three injections for the 
deposition of the anesthetic solution are necessary. The first injection 
is applied near the mandibular foramen, the second near the mental 
foramen, and the third into the incisive fossa. To locate the mandibular 
foramen in the mouth, the lingual surface of the ramus is palpated with 
the finger, the anterior sharp border of the coronoid process is easily 
felt about five-eighths of an inch posterior of the third molar. The 
process passes downward and backward of the third molar, and enters 
into the external oblique line. Mesially from this ridge is to be found a 
small triangular concave plateau, which is facing downward and outward, 
being bound mesially by a distinct bony ridge and covered with mucous 
membrane. As there is no anatomical name attached to this space, 
Braun has called it the retromolar triangle (trigonum retromolare). In 
the closed mouth it is located at the side of the upper third molar, and 
in the open mouth it is found midway between the upper and lower 
teeth. Immediately back of the mesial border of this triangle, directly 
beneath the mucous membrane, lies the lingual nerve, and about three- 
eighths of an inch farther back the mandibular nerve is to be found. 
This last nerve lies close to the bone, and enters into the mandibular 
foramen, which is partially covered by the mandibular spine. 

Before starting the injection the patient should be cautioned to rest 



TECHNIQUE OF INJECTION 641 

his head quietly on the head-rest of the chair, as any sudden movement 
or interference with the hand of the operator may be the cause of break- 
ing the needle in the tissues. The syringe, provided with a one-inch 
needle, is held in a horizontal position, resting on the occluding surfaces 
of the teeth from the cuspid backward and slightly toward the median 
line. The needle is to be inserted three-eighths of an inch above and 
the same distance back of the occluding surface of the third lower molar, 
the needle opening facing the bone. This position will insure the 
correct direction of the needle point so as to reach the tissues immediately 
surrounding the nerves, and not lose the injection in the adjacent thick 
muscle tissue. The needle must always be in close touch with the bone, 
and is now slowly pushed forward, depositing a few drops of fluid on 
its way until the ridge is reached. About five drops of fluid are injected 
in this immediate neighborhood for the purpose of anesthetizing the 
lingual nerve. The needle is now pushed very slowly forward, always 
keeping in close touch with the bone and depositing fluid on its way, 
until it is pushed in about five-eighths of an inch. It is important to 
feel the way carefully along the bony wall of the ramus, as the needle 
may have to pass over the roughened and bony elevations, which afford 
attachment to the internal pterygoid muscle. During the injection the 
syringe should remain in the same horizontal position as heretofore 
outlined. Soon after the injection, paresthesia of one-half of the tongue 
on the side of the injection occurs, which is soon followed by anesthesia 
of the mandibular nerve. Paresthesia of the mucous membrane and 
half of the lower lip is also established. The pulps of the lower teeth, 
including the cuspid and lateral incisor and the gum tissue on both sides 
of the jaw, are anesthetized, including a part of the anterior floor of 
the mouth. The complete anesthesia of the two nerves also anesthetizes 
the whole alveolar process in this region. About five minutes are re- 
quired for the complete anesthetization of the lingual nerve, and at least 
fifteen minutes for the mandibular nerve. Braun claims that the injec- 
tion is absolutely free from danger, while Roemer states that danger may 
arise if the whole quantity of the solution should accidentally be injected 
into a vein. 

Conductive mandibular anesthesia is possible only when the patient 
can open the mouth sufficiently to allow the ready introduction of the 
syringe. If the tissues about the third molar are highly infiltrated with 
inflammatory exudates, local anesthesia is absolutely prohibited. 

The mental foramen lies midway between the superior and inferior 
border of the body of the mandible on its external surface, usually 
below the second bicuspid teeth. Its opening always faces posteriorly. 
An injection near this point increases the anesthesia in the bicuspid 
region. The incisive fossa is a shallow depression on the external 
surface of the mandible between the cuspid teeth. It may be located 
by the palpating finger immediately above the chin. A number of small 
41 



642 LOCAL ANESTHESIA 

foramina are found in this region for the passage of nerves and nutrient 
vessels. The lower incisors may be anesthetized by making injections 
anteriorly into the incisive fossa and one posteriorly in the region corre- 
sponding to the fossa. Usually, peridental anesthesia is to be preferred 
for these teeth. 

Conductive anesthesia is serviceable if a number of teeth have to be 
removed at one visit. It should be borne in mind, however, that in 
general only one-half of either jaw should be anesthetized at one 
sitting, so as to keep the quantity of the injected anesthetic solution 
within the limits of ordinary dosage. 

The Injection into the Pulp. — By pressure anesthesia, pressure cata- 
phoresis, or contact anesthesia, as the process is variously termed, we 
understand the introduction of a local anesthetizing agent in solution 
by mechanical means through the dentin into the pulp for the purpose 
of rendering this latter organ insensible to pain. Simple hand pressure 
with a suitable instrument, the hypodermic syringe or the so-called high 
pressure syringe, is recommended for such purposes. Regarding the 
principles of pressure anesthesia, it should be remembered that we 
cannot force a liquid through healthy dentin by a mechanical device 
without injury to the tooth itself. If a cocain solution is held in close 
contact with the protoplasmic fibers of the dentin, the absorption of 
cocain takes place in accordance with the law of osmosis. The imbib- 
ition of the anesthetic is enhanced by employing a physiological salt 
solution as a vehicle. On the other hand, living protoplasm reacts 
unfavorably against the ready absorption of substances by osmosis 
for two reasons: (1) Its albumin molecule is relatively large and not 
easily diffusible, and (2) as an integral part of its life it possesses "vital" 
resistance toAvard foreign bodies. These latter factors are sufficiently 
demonstrated by the fact that it is very difficult to stain living tissue. 
Dehydration of the protoplasm increases the endosmosis of the anes- 
thetic solution markedly. 

When we apply the same "pressure" anesthesia upon carious dentin, 
the above statements do not hold good. We are able to press fluids 
quite readily through carious dentin. We must bear in mind that such 
dentin has been largely deprived of its inorganic salts, leaving an 
elastic spongy matrix in position. By drying out this dentin and then 
confining the anesthetic solution under a suitable water-tight cover, 
the pressure applied by the finger is quite sufficient to obtain the 
results. Colored fluids may be readily pressed through such dentin 
and even stain the pulp. 

In teeth not fully calcified and in so-called soft teeth, pressure anes- 
thesia is more readily obtained, while, according to Zederbaum, the 
process fails in "teeth of old persons, teeth of inveterate tobacco chewers, 
worn, abraded, and eroded teeth, teeth with extensive secondary calcific 
deposits, teeth whose pulp canals are obstructed by pulp nodules, teeth 



TECHNIQUE OF INJECTION 043 

with metallic oxids in tubules, teeth with leaky old fillings, badly calci- 
fied teeth — mainly all from one and the same cause, namely, clogged 
tubuli. In most cases no amount of persistent pressure will prove 
successful." 

From the foregoing it will be observed that the so-called high pressure 
syringes possess little merit relative to pressure anesthesia. The pressure 
which can be produced by a good working all-metal syringe, holding it 
between the index and middle fingers and forcing the piston with the 
thumb, amounts to 250 to 300 pounds in the average man. The pressure 
required in pressure anesthesia to produce a perfect contact is usually 
much less than the above force. 

Methods of Anesthetizing the Pulp. — 1. The pulp is wholly or partially 
exposed: Isolate the tooth with the rubber dam and clean it with 
water and alcohol. Excavate the cavity as much as possible, and if the 
pulp is not exposed, dehydrate with alcohol and hot air. Saturate a 
pledget of cotton or a piece of spunk with a concentrated cocain or 
novocain solution, place it into the prepared cavity and cover it with 
a piece of vulcanizable rubber, and with a suitable burnisher apply 
slowly, increasing continuous pressure from one to three minutes. The 
pulp may now be exposed and tested. If it is still sensitive, repeat 
the process. Loefrler states that "this pressure may be applied by 
taking a short piece of orange wood, fit it into the cavity as prepared, 
and direct the patient to bite down upon this with increasing force. 
In this way we can obtain a well-directed regulated force or pressure, 
and with less discomfort to the patient and operator." Miller described 
this process as follows: "After excavating the cavity as far as convenient 
and smoothing the borders of it, take an impression in modelling com- 
pound, endeavoring to get the margins of the cavity fairly well brought 
out; put a few threads of cotton into the cavity and saturate them thor- 
oughly with a 5 to 10 per cent, solution of cocain, cover this with a 
small bit of rubber dam, and then press the compound impression 
down upon it. We obtain thereby a perfect closure of the margin, so 
that the liquid cannot escape and one can then exert pressure with the 
thumb sufficient to press the solution into the dentin." 

2. The pulp is covered with a thick layer of healthy dentin: With 
a very small spade-drill bore through the enamel or direct into the 
dentin at the most convenient place, guiding the drill in the direction of 
the pulp chamber. Blow out the chips, dehydrate with alcohol and hot 
air, and apply the syringe provided with a special needle, making as 
nearly as possible a water-tight joint. Apply slow continuous pressure 
from two or three minutes. With a round bur the pulp should now be 
exposed, and if still found sensitive, the process is to be repeated. 

Recently a method has come into vogue which allows successful 
anesthetization of the pulp by injecting the anesthetic solution around 
the apex of the tooth. The spongy alveolar process, which contains 



644 LOCAL ANESTHESIA 

lymph channels, allows the ready penetration of the fluid. The injection 
should be made close to the bone, pushing the needle slowly toward the 
apex, while the fluid is deposited drop by drop. No wheal should be 
raised by the injection, otherwise the benefits of the pressure from the 
dense gum tissue is lost. 

According to Hertwig, the protoplasm of the cell primarily transfers 
irritation, and, secondly, transmits absorbed materials. Therefore, the 
anesthetic solution has to pass through the entire dentinal fiber before 
the nerve tissue of the pulp proper is reached. Consequently a certain 
period of time is required before the physiological effect of the anes- 
thetic is manifested. This period of latency is dependent upon the 
thickness of the intermediate layer of dentin or bone. The successful 
anesthetization of the pulp depends largely upon this most important 
factor of allowing sufficient time for the proper migration and action of 
the drug. 



LOCAL ANESTHESIA FOR OPERATIONS ABOUT THE MOUTH, 
EXCLUSIVE OF THE EXTRACTION OF TEETH 

In operating about the mouth for an abscess, a cystic or a solid tumor 
of the approximate size of a large walnut, a malposed tooth, or for any 
other purpose, the rhomboid infiltration according to Hackenbruch 
affords the simplest means of producing a most satisfactory anesthesia. 
After previously cleansing the field of operation with an antiseptic 
solution, a very small drop of phenol is placed at a and b (Fig. 677) 

Fig. 677 



to obtund the point of puncture superficially. The needle is quickly 
thrust through the mucosa at a, and at once slow pressure is exerted on 
the piston, moving the needle steadily along the external line of the 
tumor. The needle is now partially withdrawn, without, however, 
leaving the original puncture, and a second injection or as many as 
may be needed are made in opposite directions. This maneuver is now 



OPERATIONS ABOUT THE MOUTH 645 

repeated at b, and thus a circumscribed infiltration of the whole tumor 
is obtained. If the tumor, etc., is very large, additional punctures and 
injections may be made as outlined in the schematic drawing. After ten 
to fifteen minutes' waiting the extirpation of the tumor may be begun. 
For injecting the soft tissues other than the gum, a 1 per cent, novocain- 
adrenalin solution — one tablet dissolyed in 2 c.c. of water — is quite 
sufficient. 

The anesthetization of the soft and hard palate is comparatively 
easily accomplished. The injection on the hard palate is started at the 
gingival edge of the alveolar periosteum on both sides of the jaw toward 
the median line. As the gum tissue is extremely dense, great force is 
required for a complete infiltration in this region, and only small quan- 
tities of the solution are required. The soft palate is easily infiltrated 
by inserting the curved needle posteriorly to the third molar. 

Small tumors and cysts on the tongue or the floor of the mouth are 
best anesthetized by the rhomboid infiltration of Haekenbruch. For 
the complete extirpation of a ranula, the injection is made into the 
cyst wall near the periphery, after which the cyst is slit open and a 
small quantity of the anesthetic solution is injected into the inner surface 
of the cyst. Large cysts, tumors, and major operations on the tongue 
require the anesthetization of both lingual nerves. In injecting and 
operating on the floor of the mouth, the index finger of the left hand 
should be placed on its external surface as a guide to die needle or the 
knife. 

Local anesthesia is indicated in all minor and in relatively many 
major operations on the mucous surfaces, the skin, and the teeth. 
Local anesthesia is not a substitute for general anesthesia; its usefulness 
is materially increased by familiarizing one's self with the modern 
methods of its production and with a perfect mastering of the technique. 
The danger of poisoning has been practically eliminated by using iso- 
tonic solutions containing a relative small percentage of the anesthetic 
in combination with the alkaloid of the suprarenal capsule. Even 
if the danger of o-eneral narcosis is small under the very best conditions, 
the danger from local anesthesia is always less. The greater majority of 
all dental operations can be safely carried out under local anesthesia, 
provided the operator has acquired a complete working knowledge of 
the various components which, as a whole, constitute this important 
branch of dental therapeutics. 



CHAPTER XIX 
PLANTATION OF TEETH 

By LOUIS OTTOFY, D.D.S. 

The transplantation of a tooth signifies the insertion of a natural 
tooth into a natural alveolus other than the one it originally occupied. 
The tooth may be an old and dry specimen transplanted into an alveolus 
from which a tooth has been recently removed, or it may be a freshly 
extracted tooth transplanted from one part of the mouth of an individual 
to another part of the mouth of the same individual, or it may be a 
freshly extracted tooth transplanted from the mouth of one person 
into that of another. 

Replantation signifies the replacing of a tooth in the alveolus whence 
it had been removed by design or accident. The operation may be 
performed at once or at any time before the socket is filled with new 
tissue. 

Under the term implantation are included all those operations which 
involve the formation of an artificial alveolus for the reception of the 
root of a human tooth. The operation of altering the size or form 
of an existing alveolus to receive a tooth belongs to this class, although 
it is a combination of transplantation and implantation. 

The operation of replantation probably far antedated that of trans- 
plantation, as the latter preceded implantation, but its definite history 
is unknown. It is safe to presume that it has been practised ever since 
mankind conceived of the natural healing power of the body. Even 
when performed with crudity and without any clear comprehension 
of the mode of repair, favorable results have been reported. The 
operation is at present an uncommon one; the condition for the relief 
of which it was at one time practised with comparative frequency, 
chronic alveolar abscess, has been found amenable to less radical 
treatment. 

The operation of transplantation is first noted in the writings of 
Ambroise Pare in the sixteenth century, although credit has generally 
been given to Dr. John Hunter, who gave the subject considerable 
attention. Hunter's experiment of implanting a tooth in the comb 
of a cock is classical. The records of the operation do not exhibit 
any great measure of success attending it. Hunter noted cases of 
transplantation of dead teeth which remained for years. 

No one disputes with Dr. Younger, of Paris, the authorship 
(646) 



BIOLOGICAL COXDITIOXS IX PLAXTATIOX 



64: 



of the operation of implantation. The date of his first operation 
was June 15, 18S5, although Bourdet in 1780 was the first to mention 
the operation, stating that "irresponsible persons claim to make a 
socket, and implant into it a tooth." An attempt at partial implanta- 
tion is recorded in Dental Cosmos, vol. xix, p. 258. 

In order that an intelligent conception may be had of the intimate 
nature of the biological conditions which surround the teeth after inser- 
tion by either of these operations, it is essential to study the general 
processes which attend the repair of tissues, and their behavior toward 
foreign bodies. 



Fig. 678i 



Fig. 679 







mix 
mi. 




m 



*m* 




1 5 1 

A tooth and its normal attachment and vas- 
cular supply: 1, 1, apical pericementum in which 
is seen the main pericemental artery, 5; 2, 2, anas- 
tomosing bloodvessels or channels of the alveolar 
walls; 3, 3, the marginal anastomosis of alveolar 
and pericemental arteries. 



Conditions following replantation: 1, l', 
the pericementum and inflammatory effu- 
sion between pericementum and alveolar 
walls; 2. 2. source of blood supply to the 
area of repair; 3, 3. terminations of alveolar 
arteries; 5. obliterated apical artery. 



As all of these operations are performed under the strictest antiseptic 
precautions, the consideration of bacterial influence is omitted at this 
juncture. As it is impossible to secure specimens which would show 
these several parts in their true relations, the illustrations are neces- 



sarily diagrammatic and theoretical. 



Fig. 678 exhibits a longitudinal section of an incisor, its attachments 
and support, together with its vascular supply, in its normal relations, 



Figs. 678 and 681 are from drawings by Dr. H. H. Burchard. 



648 



PLANTATION OF TEETH 



the bloodvessels from the pericementum anastomosing with those of 
the alveolar periosteum. The pericemental space is filled with fibrous 
tissue. To avoid confusion the nerves and veins have been omitted. 
Fig. 679 represents the conditions following replantation. The tooth 
has been sterilized and its pulp canal hermetically sealed. The peri- 
cemental bloodvessels have been destroyed in extraction. Portions of 
the pericementum are seen clinging as fibrous remnants to the cemen- 
tum. The remainder of the alveolus is filled with inflammatory cor- 



Fig. 680 



Fig. 681 




Conditions following transplantation: 
1, ]/, embryonic tissue which will be 
organized into repair tissue replacing 
the original pericementum; 5, obliterated 
apical v< 




Conditions following implantation: 1, 1, 
alveolar arteries; 2, 2, gingival margin; 3, 
inflammatory still unorganized tissue filling 
the space between the cementum and walls 
of the artificial alveolus; 4, 4, phagocytes, 
multinucleated cells attacking cementum of 
implanted tooth; 5, obliterated apical 
vessels. 



puscles. The vascular supply to the regenerated pseudo-per icemen turn 
is derived first from the vessels of the alveolar periosteum via the alveolar 
process. 

Fig. 680 shows the conditions existing soon after the operation of 
transplantation. The mechanical violence of extraction has irregularly 
enlarged the natural alveolus. The tooth, its apex rounded, is shown 
with the blunted extremity. The vascular supply is similar to that 
of Fig. 679. The alveolar space is filled with inflammatory corpuscles. 

Fig. 681 exhibits the conditions probably existent soon after an 
implantation operation. The vascular supply is the same as shown 



REPLANTATION AND TRANSPLANTATION 649 

in Figs. 679 and 680. Instead of having a layer of periosteal bone, 
the formation of the artificial alveolus is into the spongy medullary 
bone. The artificial alveolus, being necessarily different in size and 
outline from the tooth, is filled with inflammatory products. Some of 
the cells, becoming multinucleated, are seen to be exercising their phago- 
cytic — in this connection, resorptive— function upon the cementum. 



REPLANTATION AND TRANSPLANTATION 

Replantation. — In the present state of dental practice the following 
conditions may be regarded as warranting replantation: 

1. When a tooth has been dislodged by traumatism, a blow by a 
ball, club, or fall, etc. 

2. When a tooth has been accidentally removed by the slipping of 
the forceps during the performance of a dental extraction. 

3. When some disease, otherwise incurable, affects either the root 
or some portion of its alveolus. 

The first two causes are practically the most frequent under which 
replantation is justifiable. 

In case a tooth has thus been dislodged and found, it should at once 
be cleansed of all foreign matter and then be carefully examined for 
fractures or other injury. Any cavities present should be filled, the 
contents of the root canal removed, and the space filled in the manner 
described later; fractured or abraded portions or surfaces are to be 
made smooth, and the tooth placed in an antiseptic solution. A careful 
examination of the socket should then be made. It will be noticed 
when the accident has befallen a young individual, that as a result 
of the flexibility of the bone, the alveolar process is seldom fractured — 
an accident more prone to happen in adult life. 

Some discrimination should be exercised as to the promptness with 
which to replant the tooth. If there is considerable inflammation 
as the result of injury, it is not advisable to replace the tooth imme- 
diately. In that event the socket should be made aseptic and if possible 
normal hemorrhage reestablished. As a general rule, several days 
should be allowed to intervene when the inflammation is excessive; 
otherwise a tooth may be replaced at any time as soon as it has been 
prepared. 

The governing pathological principle is as follows: Immediately 
after an injury, a certain amount of inflammation takes place and there 
is retrograde metamorphosis — a destruction or breaking down of tissue; 
and this is not the most favorable time to expect re-attachment to take 
place. As a rule, within a few days a building-up process, constructive 
metamorphosis, has set in, and the replacement of a tooth at this time 
is likely to be followed by more favorable results. This period sets in 



G50 PLANTATION OF TEETH 

at any time from three days to a week, the socket being then partially 
filled with active living cells. Just prior to the replacement of the 
tooth the socket and the gum surrounding it having been cleansed and 
sterilized, the tooth itself being brought forth from its antiseptic medium, 
it must be promptly replanted. As a rule, constant but not severe 
pressure will permit the tooth to assume its original position in the 
socket, although sometimes it is necessary to remove a part of the apex 
of the root or slightly deepen the socket by means of a suitably shaped 
bur. It happens occasionally that the location of the tooth and the 
general surroundings are such that a tooth like this may be retained 
without any further attachment, but, as a rule, it is not safe to trust 
to uncertainties regarding the retention of the tooth. An impression 
of the tooth and its neighbors can be quickly secured with Melotte's 
compound or in clay, a die is easily made, from which a cap, such as 
will be described, is quickly made. 

It is needless to dwell upon the second cause mentioned. No dentist 
can ever be excused for accidentally removing a sound tooth, but in 
case the accident does happen the above procedure is indicated. 

The opportunities enumerated under the third section are also, 
fortunately, exceedingly rare. The cases in which formerly replantation 
was resorted to, on the ground that the case was incurable, are now 
much less frequently met with, and when they are encountered they 
often yield to treatment, which is now more clearly understood — such as 
amputation of the root, removal of the necrosed portion of the alveolar 
process, etc. When, however, it has been decided to extract a diseased 
tooth and to replant it, diseased portions of the root should be removed 
and a sufficient time allowed to elapse before replantation for the 
socket and tissues to have assumed a healthy aspect, even if this should 
necessitate the enlargement of the socket. 

In case of pyorrhea alveolaris, which sometimes has been suggested 
as coming under this class, treatment by replantation is out of the 
question, provided the case has made sufficient progress to suggest 
such a course. Replantation implies the presence of a socket, and 
when pyorrhea alveolaris has made any great degree of progress, the 
socket is wanting. Hence it is but in rare cases that an attempt to 
cure by this method is justifiable. 

Dr. Louis Jack 1 has recorded marked success in several cases attend- 
ing an operation of modified replantation for the cure of some of the 
earlier phenomena of phagedenic pericementitis, notably the common 
malposition due to what has been termed voluntary tooth movement. 

Transplantation. — There is a broader range for the practice of trans- 
plantation than either of the other operations treated in this chapter. 
As has been seen, replantation is limited in its application, and implan- 

1 See Transactions Academy of Stomatology, 1895. 



PREPARATION OF TEETH FOR PLANTATION 651 

tation must, from the nature of the operation, be also confined to a 
comparatively circumscribed sphere. 

The operation may be performed at any period of an individual's 
life, although, as a rule, young, vigorous, and mature adult life offers 
the greatest promise of success. Any socket in any part of the mouth, 
when placed in a healthy condition, is a more or less favorable location 
for the reception of a tooth about to be transplanted. It is true that 
sometimes a socket needs to be enlarged or deepened for this purpose, 
but this is a comparatively simple matter. Before the advent of the 
intelligent practice of crown-and-bridge work, treatment of diseases 
of the pulp and peridental membrane, the bleaching of teeth, and the 
intelligent practice of orthodontia, transplantation was resorted to as 
a remedy for the correction of many trivial disorders. In the light 
of the present day, transplantation is confined to sockets whence teeth 
have been removed for any cause which could not be remedied by some 
other method of treatment — sockets which remain as the result of 
the loss of teeth from accident of any kind (the lost teeth not having 
been recovered) ; from which roots beyond salvation have been extracted ; 
from which diseased teeth must be removed; from which roots have 
been removed, having carried crowns or having served as abutments 
for bridges until their period of usefulness has passed. 

The same rule laid down for the care of a socket previous to replan- 
tation holds good for transplantation; namely, that inflammation must 
be reduced, and the tooth transplanted into the socket at a time when 
progressive constructive metamorphosis is taking place. This period 
is stated as usually from three to seven days after the removal of the 
tooth. In instances where considerable disease, such as a chronic 
alveolar abscess of years' standing has been present, even a longer 
time should be allowed to intervene before transplantation. 



PREPARATION OF TEETH FOR PLANTATION 

With the exception of such special directions as are necessary in 
each class of the operations described in this chapter, the following 
general directions are applicable to all cases : 

The Scion Tooth. — For replantation a recently dislodged tooth is 
supposed to be at hand, hence there is a fresh tooth. For transplanta- 
tion it is implied that the tooth is either at hand or about to be secured, 
but in a case of transplantation or implantation the age of the tooth 
may be unknown and indefinite. Teeth have been planted whose 
age and origin have been absolutely unknown, and they have become 
firm in their new locations. Nevertheless it seems reasonable to take 
the ground that whenever it is possible, teeth should be fresh and some- 
thing of their previous environment should be known. There are no 



652 PLANTATION OF TEETH 

cases on record where disease has been transmitted through the medium 
of a planted tooth, although portions of the early literature of this 
subject do indicate such results. The principal objection to old and 
dry teeth is that, the water having been evaporated, these teeth are 
almost invariably fractured or cracked from shrinkage. When these 
fractures extend to the crown portion, the enamel frequently chips 
off within a short time after the tooth has been planted; while in some 
instances the entire root has been fractured. Another objection to 
teeth promiscuously gathered is that it is seldom possible to find teeth 
in which the crowns are sufficiently perfect to be serviceable and to 
be presentable in the mouth. The crown of a dry tooth permits of 
but slight alteration with the grinding stone or sandpaper disk with- 
out endangering its integrity; while if it is affected by caries to such 
an extent as to require an extensive operation, the life of the filling 
is likely to be of shorter duration than a similar operation performed 
on a freshly extracted tooth or a tooth with living connections. For 
this reason it is preferable to use only the roots of teeth, attaching to 
them artificial crowns. This permits the selection of a crown suitable 
in size, color, and shape, and which may be ground for articulating 
purposes — an important matter in these cases. 

If, therefore, an old, dry tooth must be used, let it be carefully selected 
with regard to the absence of checks or cracks or fractures, and if it 
be impossible to secure a tooth with such a crown, let there be selected 
a good root to which a crown, as described later, can be attached. 

If a freshly extracted tooth can be secured, even though the crown 
may be slightly carious, the necessary filling operation is advisable, 
and such a tooth should be used, if possible. 

Root- tilling. — Roots may be filled either from the apex or through 
an opening or cavity in the crown. Gutta-percha seems to answer 
all the necessary purposes, but for a short distance from the apical 
extremity it is well to fill with gold wire or foil. 

Pericementum. — The theory that the pericementum becomes revivified 
does not seem to be tenable; at least the proposition that life is main- 
tained in the pericementum for any considerable period of time after 
the tooth has been removed from vital attachment is not in accord 
with general physiological laws, although periosteum as a tissue, main- 
tains its vitality for a time after separation. 1 For the purpose of secur- 
ing an attachment there is no necessity for the presence of the peri- 
cementum; but it is reasonable to assume that the nearer to natural 
states the root and the socket are in, the more favorable will be the 
prognosis. It is, therefore, a safe rule to follow, to preserve as much 
of the pericementum as is possible. The preservation of the peri- 
cementum has an advantage from the fact that after the tooth has been 

1 See Ziegler's General Pathology. 



PREPARATION OF TEETH FOR PLANTATION 653 

planted, the pericementum under the influences of bodily heat and 
moisture expands and thus acts in the nature of a sponge graft, enabling 
the tissues more quickly to obliterate spaces which are present and 
to attach themselves to the root. 

Subsequent Care of Planted Teeth. — Numerous methods for the reten- 
tion of planted teeth have been recommended by various authors at 
different times. While many of them are original and ingenious, all 
are to be condemned except those means which look to the firm, rigid, 
immovable retention of the planted tooth for a definite period, that 
of surgical repair. Neither the rubber-dam splint, silk ligature, nor 
gold or other metal wire comes under this heading. Planted teeth 
must be retained immovably for a period of two to six weeks, occasionally 
from two to eight, ten, or twelve weeks. The shortest time of immobility 
consistent with subsequent attachment is preferable. The tooth to 
be transplanted or implanted should be fitted after preparation in a 
model, made from an impression of the gum where the tooth is to be 
planted and of the adjoining teeth, as shown in Fig. 682. 

Fig. 683 





Model showing prepared tooth in place: (a) gold Model showing retention cap in situ, 

filling at cervical joint. 

An impression is then taken of it and of the adjoining teeth on each 
side. A retention cap is then swaged to cover the grinding surfaces 
of three or more teeth, half the length of the crown on the labial surface 
and nearly the full length on the lingual or palatal surface, as shown 
in Fig. 683. 

The cap may be made of pure gold, platinum, or German silver. 
The gauge, according to the metal used, should be from No. 32 to 
No. 38. This cap is cemented upon the crowns adjoining the planted 
tooth in such a manner that it may be removed without disturbing 
the planted tooth. The operator can remove the cap by springing the 
metal away from the teeth, examine the condition of attachment of 
the planted tooth, and replace the cap if it should be necessary. When 
the articulation interferes with the retention of the cap, the latter may 
be ligated to the adjoining teeth in addition to being cemented to them, 
and still admit of removal without disturbing the planted tooth. There 



654 PLANTATION OF TEETH 

is at present no method of ligaturing or banding the teeth which will 
permit removal of the ligature or band without more or less disturbance 
of the planted tooth. 

Aside from the necessity of immobility for a certain period, the planted 
tooth and surrounding tissue generally require but little attention. 
In occasional cases the tissues may be stimulated by painting the gum 
with a mixture of equal parts of tincture of aconite root, chloroform, 
and iodin paint (the latter is a saturated solution of iodin in alcohol), 
or by the use of stimulating mouth washes, notably those containing 
capsicum. The patient should be cautioned to encourage the down- 
ward growth of the gum by the use of the toothbrush, to prevent the 
accumulation of remnants of food or saliva, and to prevent their 
subsequent putrefaction should particles become unavoidably lodged 
around the tooth or cap. This is best accomplished by using a cameFs- 
hair brush dipped in hydrogen dioxid or pyrozone, electrozone, phenol- 
sodique, etc., and washing out the interstices frequently. A syringe 
or spray from an atomizer may be used. 

Artificial Roots. — Experiments have been performed looking toward 
the use of roots other than those of natural teeth. Roots made of 
ivory, corrugated or perforated porcelain, lead, gold, platinum, and 
other metals have been used. The writer's experiments in this direc- 
tion have all resulted in failure. There is no recorded evidence that 
any have resulted successfully. 

Mode of Attachment. — As to the mode of attachment of planted teeth 
the subject is clouded in obscurity. From the nature of the conditions 

it is difficult to secure definite information. 
fig. 684 Dr. Younger holds to the belief that the 

pericementum becomes revivified, and hence 
the attachment is almost physiological. It 
is probable that the filling of the space 
around the root of the tooth with compact 
bone tissue is sufficient to account for the 
retention of the tooth by bony encapsula- 
tion or ankylosis. It is probable that a 
planted tooth, by reason of the absence of 

An implanted tooth in situ: ,1 i • « iij.it* 

a, a, excavations of the cementum the Cushion formed by the living pen- 
due to resorptive process. cementum, causes more or less irritation 

in the socket through the impact of use in 
mastication, and that this irritation leads to resorption of the root; that 
in this resorption and the subsequent filling up of these resorbed surfaces 
are found reasons for the success of the operation. Fig. 684, at a, a, 
shows how a partially resorbed root may be retained in place. The 
length of time during which a planted tooth is retained depends entirely 
upon the rapidity of the resorptive process and the activity of the tissues 
in maintaining a healthy condition. Replanted and transplanted teeth 




PREPARATION OF TEETH FOR PLANTATION 655 

have been known to do good service for from twenty to forty years. The 
time of the observation as to implanted teeth is shorter, the oldest cases 
being less than twenty years old. In the writer's observations, extend- 
ing over a period of nearly eighteen years, a number of teeth have been 
noted which have been retained successfully for ten years; how much 
longer they will remain serviceable, and what percentage of success 
will attend later cases, will require further time to determine. Dr. 
Younger has had successfully implanted teeth under observation, at 
last report, for eleven years. 

Precautions. — There is no special danger connected with any of the 
operations described in this chapter, provided the usual antiseptic 
precautions are observed and dangerous anesthetics avoided. Aside 
from these, during the operation of replantation and transplantation 
no special skill is necessary; certain precautions are, however, essential. 
Inasmuch as implantation is an essentially esthetic operation, it should 
be borne in mind that it is confined principally to the ten anterior teeth, 
and that it is more frequently performed in the upper jaw than in the 
lower. The territory involved is therefore limited. The operator who 
contemplates forming in this territory a socket for the reception of the 
root of a tooth should be intimately acquainted with the anatomical 
and histological relationships of the various parts. 

In the first place it should be remembered that when alveolar resorp- 
tion has taken place, the relative depth of bone is considerably less 
than when a tooth is still in situ and surrounded by the normal alveolar 
process. The operator must, therefore, not penetrate deeper into the 
bone than the original depth of the socket may have been. Indeed, 
it is not, as a rule, necessary to penetrate so far. 

In the upper jaw the principal danger in making a socket for the 
reception of central incisors lies in the proximity, posteriorly, of the 
anterior palatine nerve, artery, and vein, which have their exit from 
the bone through its foramen, often near the roots of these teeth. With 
the lateral incisor the principal precaution necessary is the preservation 
of the labial plate of the alveolus. If the lost tooth has been absent 
for some time, and much resorption has taken place, it is sometimes 
impossible to drill a socket so that the tooth has a proper direction 
and prominence in the arch, and yet be able to secure a bone covering 
for its labial surface. As a rule, there is sufficient process in the canine 
region to enable the operator to secure all the attachment desirable. 
The bicuspid and molar regions present the danger of perforation 
of the floor of the maxillary sinus. This is liable to happen anywhere 
from the first bicuspid to the second molar. Extreme caution should 
be exercised to avoid it. In two instances in practice the perforation 
was followed by no unpleasant complications. Care was taken not 
to infect the sinus, the teeth were implanted in the usual manner, and 
the cases resulted successfully. Subsequently one of these teeth was 



656 PLANTATION OF TEETH 

lost, but during the process of root attachment or encystment the 
perforation into the sinus was closed. 

In the lower jaw the principal difficulties encountered are the follow- 
ing: In the incisive region there is a deficiency of alveolar process, 
and hence much difficulty is encountered, at times, in securing a suffi- 
ciently deep bony socket. At the location of the canine tooth the lower 
jaw becomes broader and there is usually sufficient room to enable 
the making of a good socket. In the premolar region the principal 
precaution necessary is in regard to the mental foramen. It must 
be borne in mind that normally the exit of the nerves and vessels at 
this point is directly below the second bicuspid tooth, and that when 
resorption of the alveolar process has taken place this foramen is often 
near the upper border of the jaw. From this point posteriorly implanta- 
tions are rarely performed, and when done the principal precaution 
must be in regard to the inferior dental canal, which is near the surface 
if much resorption has taken place. 

Artificial Crowns. — The precautions necessary in the selection of 

a tooth for transplantation or implantation have been noted, and it 

might be proper at this time to describe the prepa- 

Fig. 685 ration of a root w T ith an artificial crown, presuming 

that it is only in rare instances that a suitable 

entire natural tooth can be obtained. Attention 

was called to the necessity of securing asepsis of 

the root, and the filling of the root canals has been 

described. The most suitable form of crown has 

... .. been found to be the Logan, which is ground to 

Natural root with arti- m m . 

ficiai crown. suit the occlusion and cemented into the root canal 

without much regard as to a careful fit at the cervix 
of the crown to the root. After the cement has hardened, the margin 
between the root and crown is prepared with engine burs, and a 
filling of gold introduced, making a circle around the tooth. When 
this is polished down there is a perfect gold filling level with the 
root and crown, which is preferable to a soldered band (Fig. 685). 

A similar result may now be much more satisfactorily obtained by 
adapting the crown to the root end with casting wax and, after carefully 
trimming to shape, withdrawing the crown with lid attached, investing 
the whole and replacing the wax by a gold casting by means of any of 
the modern casting machines. 



GENERAL CONSIDERATIONS 

Asepsis. — The operations described in this chapter must always be 
performed under perfect aseptic conditions; that is, the hands and 
person, instruments and other accessories, the tooth about to be planted, 



GENERAL CONSIDERATIONS 657 

and the field of surgical operation must be maintained in a clean, 
aseptic condition. 

Any of the usual, accepted methods can be resorted to. As a rule, 
however, the drugs selected for this purpose should not be of an irri- 
tating nature. For the hands and person, pure soap followed by a 
5 per cent, solution of carbolic acid is sufficient. The instruments 
and other accessories can be kept free from inoculating bacteria by the 
use of pyrozone, formalin, euthymol, or a 5 per cent, solution of carbolic 
acid. The use of bichlorid of mercury in the proportion of 1 part to 
2000 of water is also permissible, although it is not as advisable on 
account of its irritating nature. The sterilization of the tooth about 
to be planted differs according to circumstances. A tooth whose source 
is unknown, and which has been kept in a dry state for a long period, 
will not be benefited by being placed into an antiseptic solution until 
just prior to the time when it is to be used. Hence dry teeth can be 
kept in any clean box covered with clean cotton until they are ready 
for use. After the necessary preparation hereinafter described, the 
dry tooth should be placed in a solution of glycerol and carbolic acid 
(about 5 per cent, of the latter), and just before using, it can be placed 
in a pyrozone solution or in a solution of carbolic acid and water. 
Freshly extracted teeth should, of course, have their pulp chambers 
and root canals cleansed and hermetically sealed, and then be placed 
at once in fluid, preferably in diluted glycerol to which a few drops of 
carbolic acid have been added. Teeth and roots so treated have been 
preserved for eight years. 

The field of operation may be quickly sterilized and cleansed of 
adhering mucus by mopping the surface with a ball of cotton saturated 
with hydrogen dioxid, 3 per cent, solution, just previous to operating. 

It is, of course, of exceeding importance that the socket into which 
a tooth is about to be planted shall be free from disease germs or bacteria. 
As a general rule, flowing blood is the best of antiseptics, washing away 
any bacteria which may become lodged from external sources; hence 
so long as a socket is constantly being filled with flowing blood during 
an operation but little further care need be bestowed upon it. As 
a general rule, the socket and the tissues surrounding it will react more 
quickly after operation the less the medication has been; hence the 
very slightest and mildest of antiseptics are indicated. Zinc chlorid 
2 to 5 grains to the ounce of lukewarm water, hydrogen dioxid, 3 per 
cent., or the 5 per cent, solution of carbolic acid in lukewarm water, 
give most satisfactory results. These solutions will be found quite 
sufficient to maintain the field of surgical operation aseptic. 

Anesthesia. — For the purpose of allaying pain, the use of anesthetics 
is justified when imperatively demanded; but unfortunately in certain 
cases the benefits derived are frequently outweighed by the disadvantages 
accruing from their use. 
42 



658 PLANTATION OF TEETH 

Anesthetics are either general or local. An operator would scarcely 
be justified in assuming the risks attendant upon the use of chloroform, 
ethylic ether, ethyl bromid, or any of the combinations in which these 
anesthetics are administered. Nitrous oxid would, in the majority of 
instances, be contraindicated by reason of the shortness of the period 
of anesthesia which it induces. 

There do not appear to be any records of satisfactory results with 
hypnosis. Local anesthesia, therefore, is the means generally employed. 

The method adopted has usually been confined to the injection or 
other introduction of cocain, the dose being variable, but usually about 
5 to 15 minims of a 1 per cent, solution of the hydrochlorid. For a full 
description of the technique consult Chapter XVIII on Local Anesthesia. 
A serious objection has been noted to injection through the gum, viz., 
that more or less sloughing or destruction of the tissues may result, 
and this is very unfavorable for subsequent success. In replantation or 
transplantation, sufficient anesthesia is often obtained from the wash 
used in cleansing the socket; but in implantation the formation of the 
new socket is often an exceedingly painful operation, and in these cases 
good results may be had by dipping the instrument with which the 
socket is being made into crystals of cocain, and thus by the friction 
of the instrument rubbing it into the parts that are being operated 
upon. 

The subject of anesthesia may be dismissed with the sole injunction 
that its use should be resorted to only in those instances where it is 
absolutely necessary. The majority of the cases of plantation are 
performed with no more pain than is inflicted in filling operations. 

The same care should be given to the retention of transplanted teeth 
as is given to the retention of replanted teeth. Teeth thus carefully 
transplanted, in individuals of good health, often remain useful 
for a number of years. In the past insufficient attention has been 
given to asepsis, and this, coupled with the fact that the root had 
not always been properly filled, has not resulted in as much success 
as is attained with present methods, and yet transplanted teeth are 
known to have remained in a healthy and serviceable condition for 
from twenty to forty years. 



THE OPERATION OF IMPLANTATION 

Implantation, in order to yield the best results, should be confined 
to mouths which are habitually clean and free from disease, and to a 
part of the individual's life during which the power of the developed 
mental processes is not impaired. Unclean personal habits, the 
excessive use of stimulants, and occupations calling for an unusual 
expenditure of nerve force are unfavorable. A suitable case having 



THE OPERATIOX OF IMPLANTATION 659 

been selected, an impression of the space and of the teetn adjoining 
it is taken. A plaster cast is made, the proper-sized socket drilled 
therein, the tooth is selected and prepared, either with or without an 
artificial crown in the manner previously described, the occlusion is 
adjusted, and a retention cap is made. These preliminaries having 
been satisfactorily accomplished, the case is ready for the operation. 
Under the heading of General Considerations the question of anesthesia 
has been already treated. 

The first step in the operation is the making of an incision through 
the gum tissue. A number of different kinds of incisions have been 
recommended by different operators, nearly all of them looking toward 
the preservation of the largest amount of gum tissue. Some recom- 
mend a crucial incision X, turning back the four corners of the gum 
tissue. Others have recommended an incision in the shape of the 
letter H, turning back the two flaps thus made. 

The principal objection to all of the incisions recommended lies in 
the fact that they all look toward the preservation of the gum tissue 
equally for the labial and lingual surfaces; while, as a matter of fact, 
if proper provision is made for the protection of the cervical line on the 
labial surface, the lingual surface will take care of itself, for it will be 
noticed in cutting through the gum tissue that it is much thinner where 
it reflects over the alveolar border upon its labial aspect than upon its 
lingual. Hence, frequently, if no attention whatever has been paid to 
the retention of gum tissue on the lingual surface, the neck of the tooth 
will nevertheless be sufficiently protected. 

Ftg. 686 




Incision in gum for implantation. 

Another serious objection to an incision which leaves two or more 
points or margins to be preserved, is that the tenacity of the gum tissue 
makes it utterly impossible to preserve these various flaps and pro- 
jections intact from the cutting instruments. 

The writer's method consists in an incision resulting in one flap, 
with a view of protecting the labial surface of the tooth to be implanted, 
and of preserving this single flap from injury during the progress 
of the operation. A combination, or rather a modification, of the 
most suitable incisions recommended is, therefore, the one shown in 
Fig. 686. 

This incision is made with ordinary chisels as shown in Fig. 687, 



660 



PLANTATION OF TEETH 



cutting with the chisel to and including the periosteum, lifting it forward 
and holding it out of the way of the operator by means of an instrument 



Fig. 687 




Chisels. 



Fig. 688 



tl 



similar to the one shown in Fig. 688. The operation 
thus far is usually simple and, as a general rule, not 
very painful. The drilling of the socket varies with dif- 
ferent individuals according to the density of the bone, 
the length of time that the tooth has been out, etc. In 
some instances, the reamer or trephine or knife pro- 
gresses rapidly, while in others the progress is very slow, 
or sometimes variable as the instrument enters into 
medullary spaces or passes through the more or less dense 
partitions which divide these medullary spaces from 
each other. 

The operator will determine during the operation, 
by the progress he is making with different instruments, 
which are the best to use. In some instances the entire 
socket can be made with an ordinary engine bur, while 
in others the strongest instruments especially designed for 
implantation are none too strong. In some instances an 
instrument which clears itself well during one operation 
clogs annoyingly during another. It is desirable to 
describe at this point the various useful instruments 
which have been designed and are now upon the 
market. While all of them are not necessary, some 
one or more of each class are indispensable. The tre- 
phines of Dr. Younger, of Paris, which have been im- 
proved by Dr. W. W. Walker, of New York, have (as 
shown in Fig. 689) a set-screw collar, also shown de- 
tached, which slides on the shank, and is first fixed by 
a set-screw as a gauge of the length of the tooth root. 
As will be noticed, the trephines cut only on the edge, 
and hence they do not entirely clear themselves; the 
scribed on a succeeding page are then used to 
enlarge the socket. 



■ 



Instrument for 
holding flap dur- 
ing the operation. 

reamers de- 
remove the core and 



THE OPERATION OF IMPLANTATION 



661 



The spiral knives (Fig. 690) devised by Dr. W. H. Rollins, of Boston, 
are in many cases very useful. 

They are also open to the objection of clogging. As an improve- 
ment upon these the spiral crib knife shown in Fig. 691 has the advantage 
of permitting the core to pass within it. 



Fig. 689 



Fig. 690 



o o OOO 




12 3 4 5 

Younger-Walker trephines. 




1 2 

Rollins' spiral knives. 



Dr. R. Ottolengui, of New York, has devised a set of reamers (Fig. 
693). There are nine leaves to each reamer and each leaf is divided 
into five teeth. Three of the leaves reach the apex of the cone point 



Fig. 691- 



Fig. 692 



Fig. 693 



1 2 


1 2 


Ottofy spiral 


Two forms oi Cryer's 


crib knife. 


spiral osteotome. 




12 3 4 5 

Ottolengui's reamers. 



and thus allow a more rapid forward drilling into the bone. A sliding 
collar forms a gauge to indicate the proper depth to drill. 

The reamers designed by Dr. Younger, illustrated in Fig. 694, are 
also very suitable for this purpose. Dr. Cryer's spiral osteotome — 
two forms of which are shown in Fig. 692, one with dentate edges, the 



6(52 



PLANTATION OF TEETH 



other without — is an admirable instrument for forming the artificial 
socket. 

When it is necessary to deepen or alter the shape of the socket, it is 
done very simply with either the ordinary burs of the dental engine 
or, what is preferable, a bur with a long shank such as shown in the 
accompanying illustration (Fig. 695). 



Fig. 694 



« * m 



Fig. 




I I 



W t 1 



1 2 3 

Dr. Younger's reamers. 



12 3 4 
Fngine burs with lone shank. 



The following are to be recommended: Nos. 1 and 3 of the Walker- 
Younger trephines, Nos. 1 and 3 of the Younger reamers, Nos. 1 and 
2 of the Rollins spiral knives, Nos. 1 and 2 of the Ottofy spiral crib 
knives, and Nos. 1, 3, and 4 of the Ottolengui reamers and Cryer's 
osteotome. 

During the progress of the drilling of the socket, the tooth should 
be frequently inserted until a proper adjustment has been secured. 
Occasionally these teeth can be implanted and so perfectly fitted that 
it is almost impossible to remove them with the unaided fingers; while 
at times the bone is so cancellated and the tissues so flabby that a socket, 
no matter how carefully drilled, will not retain the tooth in place. Noth- 
ing is gained by a too close adjustment of the root, as pressure must 
undoubtedly be exerted, and pressure causes resorption, and may be 
followed by inflammation. A fair, moderate fitting of the root is all 
that should be aimed at. Just before the final adjustment the socket, 
gums, tooth, and all parts contiguous thereto should be placed in an 
aseptic condition and the cap adjusted in the manner before described. 
Though the tooth may be adjusted to its socket so that immediately 
afterward it exhibits much firmness, yet in a few days subsequent to 
the operation it invariably shows less rigidity and an apparent tendency 
to loosening. This result is probably due to the resorption of those 
areas of contact between the tooth and its artificially formed alveolus 
where the greatest amount of pressure is exerted. The period of loosen- 



THE OPERATION OF IMPLANTATION 663 

ing is generally quickly followed by a progressively increasing firmness 
and immobility of the tooth caused by calcification of the exudate 
thrown out by the walls of the alveolus in the process of repair of the 
surgical injury to which it has been subjected by the operation. Planted 
teeth, when lost, are lost, as a rule, as a result of resorption of their 
roots. The process seems analogous to the resorption of the roots 
of deciduous teeth. Present records seem to indicate that resorption 
of the roots is slowest in progress in replanted teeth; it is more rapid 
in transplanted teeth, and most rapid in implanted teeth. Intelligent 
observation over replantations and transplantations extends from 
twenty to forty years. The observation of implanted cases extends at 
this writing to about twenty-five years, and successful cases have been 
under observation which have remained in the mouth over twelve 
years. The writer has the records of cases which have remained and 
done good service for the same length of time. 






CHAPTER XX 

MANAGEMENT OF THE DECIDUOUS TEETH 
By CLARK L. GODDARD, A.M., D.D.S. 

Eruption. — The first operation the dentist is called upon to perform 
for the deciduous (temporary) teeth is lancing the gums as an aid to 
eruption of those organs. This is not necessary in normal but only 
in pathological cases. Although gum tissue in its normal condition is 
comparatively insensitive, when it is inflamed it is exceedingly tender. 

The principal source of pain, however, is not in the tissue overlying, 
but when a tooth, bound down by the dense gum tissue above it, by the 
growth of its own root presses upon the formative organ below, it causes 
pain which in many cases may be so excessive as to cause reflex dis- 
orders of alarming character. 

Dr. J. W. White 1 says: "The manifestation of functional inhar- 
mony from pathological dentition will depend, as in trouble arising 
from any other disturbing cause, upon the temperament and health 
of the child, its dietetic management, and its hygienic surroundings. 
In some cases there is a gradual development of biliary, gastric, enteric, 
and cerebral complications, a slow but steady loss of vital power, with 
effort at recuperation and feeble resistance to the undermining influ- 
ences which gradually but surely wear out the young life. 

" In other cases the indications of disturbance of function are mani- 
fested primarily in the nervous system; the symptoms are all charac- 
teristic of acute derangement and are dangerous from their violence 
and uncontrollability. High fever, vomiting, choleraic diarrhea, men- 
ingitis, convulsions, stupor, and death are the rapidly succeeding 
phenomena. Between these two phases there is every conceivable 
grade of symptoms, every imaginable complication." 

By many it has been urged, as an objection to lancing the gums, that, 
in case the tooth does not erupt mmediately, cicatricial tissue is formed 
over it which will bind the tooth down more rigidily than before. Cica- 
tricial tissue is, however, of a lower degree of organization than normal 
tissue, and is more easily broken down. Furthermore it has been proved 
by actual test that teeth erupt more readily and sooner through cicatri- 
cial gum tissue after lancing than through the gum tissue in the same 
mouth over corresponding teeth that has not been lanced. 

1 American System qf Dentistry, vol. iii, p. 327. 

(664) 



ERUPTION AND DURATION 



665 



Fig. 696 





The indications for interference are not so much local as general — 
the fretfulness, inability to sleep, and other symptoms mentioned by 
Dr. White. The gum tissue over the erupting tooth may or may not 
be highly inflamed, but the absence of such inflammation 
does not contraindicate lancing. In fact some of the 
gravest systemic disturbances occur when no local mani- 
festations are evident. 

The object is to divide the gum tissue which binds 
down the tooth and to allow it free egress. The most 
suitable instrument is shaped like that shown in Fig. 
696, and sometimes used for lancing around teeth 
before extraction. It should be held like a pencil in 
writing, so that one or more fingers can form a rest and 
guide. 

For operating on the lower jaw the child is best seated 
in the lap of the operator with the head against his breast 
■By passing the left arm around the infant's head and insert- 
ing ithe left thumb in its mouth with the fingers under 
the chin, the lower jaw can be held rigidly while the right 
hand 'performs the operation. 

For operating on the upper jaw it is best to lay the 
child upon a pillow across the nurse's lap. The operator 
takes the head on ! or between his knees, opens the mouth 
by inserting one or more fingers of the left hand, and holds 
the thumb and forefinger on each side of the alveolar 
ridge, thus preventing injury to contiguous parts during 
possible struggles of the child. 

For incisors a simple longitudinal incision is made, a 
little longer than the cutting edge of the tooth. The 
lancet should be sharp, so as to easily penetrate to the 
tooth. No harm will be done except to the blade of the 
lancet. For the canines a single incision is good, but a 
crucial incision is better. Sometimes lancing is necessary 
for the canine after it is partially erupted, as the gum 
tissue, pierced by the point only of the tooth, may form a 
dense ring around this point and interfere with further 
eruption. In such a case a division of this ring in two or 
more opposite places will give relief. 

For the molars a crucial incision is best, one cut extend- 
ing from the posterior buccal to the anterior lingual cusp, 
and the next from the posterior lingual to the anterior 
buccal. Sometimes lancing is necessary for these teeth 
after partial eruption. After the cusps have pierced the gum, the 
tooth may be held back by the bands of tissue in the sulci. In such 
cases division of these bands in the same direction as before described 






Gum lancet. 




666 MANAGEMENT OF THE DECIDUOUS TEETH 

for an unerupted tooth will give relief. Sharp-pointed curved 
scissors are well adapted to this latter operation. 

Fig. 697 will illustrate the direction of the incisions described. The 
relief afforded is generally immediate. In one case a child who had 
been fretful for several days, and who had not slept at all during the 
day, was asleep in the writer's arms within five minutes after the opera- 
tion. The gum tissue is not very 
FlG - 697 sensitive, so the operation is often 

painless. The little sufferer will 
often recognize the relief obtained 
and point to other portions of the 
gums for further relief. 

Duration of the Deciduous Teeth. — 
The importance of filling cavities 
\> in the children's temporary teeth 
is often overlooked, even by den- 
tists themselves, as these teeth are 

Lines of incision in lancing: a, a, over the j i 1 l 

molars; 6, b, over the canines and incisors SUppOSed to be lost SO early as tO 

before eruption; c, c, c, over the molars render such operations unnecessary. 

and canines after partial eruption. (J. W. rr ,, . ,, . , , 

white.) I his is generally true with the in- 

cisors, is less true with the canines, 
while the molars often need attention. Fig. 634 (see Chapter XVIII) 
shows the relations of the deciduous to the permanent dentures in a 
child of about six years of age. A study of the following table will 
show that while the incisors are superseded early by their successors 
the molars are in place nearly twice as long : 

Time of eruption. Loss. Duration. 

Central incisors .... 6 to 8 months. 6th to 7th year. 5^ to 6§ years. 

Lateral 7 to 9 months. 7th to 8th year. 5^ to 65 years. 

First molars 14 to 16 months. 9th to 10th year. l\ to 9 years. 

(1 yr. 2 mo. to 1 yr. 4 mo.) 

Canines 17 to 18 months, f Inf. 8th to 10th year. 

(1^ yrs.) \ Sup. 11th to 12th year. 7 to 10 years. 

Second molars 18 to 24 months. 12th to 13th year. 10 to 11 years. 

(if yrs. to 2 yrs.) 

The temporary molars should be preserved for three reasons: 

1. To prevent the child suffering pain. 

2. To allow proper mastication of food. 

This latter is of extreme importance, as these years are especially 
important ones in the child's growth. If he is prevented by pain from 
properly masticating his food it will not be assimilated, and a habit of 
swallowing food without masticating may be continued even when the 
permanent teeth have erupted. 

3. To preserve the fulness of the arch for the permanent teeth and 
assure the correct positioning of the first permanent molar, upon which 
depends much of the regularity of the permanent denture. 



THE CHARACTER OF THE PAT I EXT 



667 



Early loss of the deciduous second molar will allow the first per- 
manent molar to move forward and occupy room that should be pre- 
served for the premolars (bicuspids). Early loss of the first temporary 
molar will allow the second temporary and the first permanent molar to 
move forward. 

The crowns of the temporary molars are much larger than the necks, 
and caries of the proximal surfaces will allow them to crowd together 
with the same result. Proximal fillings inserted should be so shaped as 
to preserve the original contour. If the first permanent molar thus 
moves forward of its natural position a smaller arch is left for the suc- 
cessional teeth. The result may be a constricted arch, a pointed arch, 
upper protrusion, or the labial displacement of the canines. 



Fig. 698 1 



4\ td. -A ~f\;s$ 



i \ 






Decalcification of the deciduous tooth. The numbers indicate years. 



THE CHARACTER OF THE PATIENT 

The conditions of operating on the deciduous teeth vary so much 
from those pertaining to the permanent teeth that a different consid- 
eration must be taken of filling materials. 

The little patients' mouths are small. They are often too young to 
reason with or to understand the purpose of the operation. They have 
been too often frightened by thoughtless remarks of their elders in 
speaking of their dentist. 

Oftentimes the first sitting must be utilized merely to make the 
acquaintance of the child, perhaps cleaning the teeth a little, or intro- 
ducing some palliative dressing in an aching tooth. The greatest care 
should be taken not to hurt the child. After it has gained a little 
experience it recognizes the benefit of the treatment, and will often 
submit to operations that older patients even shrink from. 

Odontalgia.— The first visits by children are usually for the relief 
of "toothache," and may occur at any age from two years upward. 



1 Prof. Pierce in American System of Dentistry, vol. iii, p. 639. 



668 MANAGEMENT OF THE DECIDUOUS TEETH 

The first treatment of most children's teeth should be palliative. 
In many cases a fear of the dentist has been engendered, which it should 
be the prime object to remove. Make the acquaintance of the little 
patient in the reception room, talking perhaps of things altogether 
foreign to the case in hand, and distract its attention. If the child is 
very timid, examine the teeth while it is seated in an ordinary chair, or 
in its parent's lap, and apply some dressing to relieve the pain. 

In the operating room the chair should be adjusted to its smallest 
size; a special child's seat may be used, or a cushion half the size of the 
chair seat, and not too soft. The child's head should be made comfort- 
able in the head-rest. The operator should not let the child detect him 
in an endeavor to hide instruments; the necessary ones may be shown 
to him if they arouse his curiosity, and their purpose explained. 

On account of the difficulty the child has in making himself under- 
stood, or from his not knowing what he wishes to describe, diagnosis is 
difficult. A child cannot always distinguish just where pain is felt, nor 
always remember its exact location. In most cases the first occurrence 
of pain is during mastication. 

It is necessary to ascertain whether pain is caused by an erupting 
tooth, a nearly exposed pulp, a pulp inflamed and dying, a putrescent 
pulp, or an alveolar abscess. If the nearly exposed pulp is suspected, 
test it by the application of a drop of cold water. Pain during masti- 
cation may be caused by thermal changes, by pressure of food in the 
cavity, or by pressure on a tooth whose pericementum is inflamed. 

If the tooth is aching while the child is in the chair, syringe out the 
cavity with warm water, dry it with bibulous paper, and apply a pledget 
of cotton saturated with oil of cloves, campho-phenique, or whatever 
has been found effective with permanent teeth. Fletcher's carbolized 
resin 1 has been invaluable for this purpose in the writer's practice. 
Applied on a pellet of cotton it acts as an anodyne, and the resin 
hardens in the cotton, forming with it a temporary stopping which will 
even bear the force of mastication for a few days. It is sometimes 
best to renew this dressing a few times before attempting a more per- 
manent treatment or filling. 

If the child cannot be brought to the office again within a few days, 
let the parent provide himself with a bottle of the carbolized resin and 
an inexpensive pair of dressing pliers. Instruct the patient how to 
apply the cotton dressing. This is the best domestic remedy for odon- 
talgia. Other medicaments may be used by the parent, such as oil of 
cloves, campho-phenique, etc., but their effect is much more temporary. 
A more durable dressing may be made by mixing zinc oxid and car- 
bolized resin to the consistence of putty and applying it in the cavity 

1 Carbolic acid, 

Resin (colophony) aa 5j 

Chloroform f§ss 



TREATMENT WITH SILVER NITRATE 669 

previously dried. It hardens under moisture, and makes a stopping 
that will remain, in sc$me cases, for several weeks. 

During such palliative treatment, sometimes unavoidably extended 
over several weeks or even months, the child is growing older, is gain- 
ing experience, is becoming used to manipulation, begins to recognize 
the benefit of treatment of the teeth — in a word, is being trained or 
educated for a good patient for whom more permanent operations may 
be attempted. 

Prof. L. L. Dunbar says: "As a domestic palliative always at 
hand, in the treatment of pulp exposure and restricting odontalgia, use 
ammonia on cotton; its repeated use will devitalize the pulp, at the 
same time effecting its removal by saponification. " 



TREATMENT WITH SILVER NITRATE 

More than forty years ago the application of silver nitrate for arrest- 
ing decay was advocated, but for many years no notice was taken 
of it. Within the last five years it has been advocated again, especially 
for use in the temporary teeth. The fact that it blackens the decayed 
surface is not as objectionable as with permanent teeth. Dr. Stebbins 1 
advocated the use of a solution of the crystals of silver nitrate in cari- 
ous cavities in temporary teeth. He applies it by means of a small 
stick inserted in a socket instrument as shown in Fig. 699. Many 

Fig. 699 



cases will need no further treatment, decay being completely arrested. 
Some cases will need secondary treatment after a few months. In 
many cases he advises filling the cavity with gutta-percha after the 
application. 

Dr. C. N. Peirce 2 advises saturating pieces of blotting paper with 40 
per cent, solution of silver nitrate, and keeping these on hand for 
use. 

Dr. E. C. Kirk advises the use of asbestos felt for saturation with 
the solution in preference to blotting paper or cotton. He says: 3 " The 
contact of silver nitrate with vegetable fiber of any sort involves not 
only a destruction of the fiber, but also of the silver nitrate, so that the 

1 International Dental Journal, 1891, p. 661. 2 Ibid., 1893, p. 152. 

3 Dental Cosmos, 1893, p. 667. 



070 MANAGEMENT OF THE DECIDUOUS TEETH 

preparation in a short time loses its desirable qualities." He advises 
that the asbestos felt be heated before the blowpipe before saturation, 
to burn out any organic material which may be present. 

Dr. A. M. Holmes 1 advises its use as follows for proximal cavities: 
"Cut away the walls to a V shape, and with a piece of gutta-percha, 
softened by heat, of the proper size to fill the space, bring the surface 
to come in contact with the diseased part of the teeth, into contact with 
the powdered crystals of silver nitrate and carry it to the place in the 
tooth or teeth prepared for its reception, packing it firmly and leaving 
it there to be worn away by use in mastication. When that takes place 
the surfaces of the teeth treated will be found black and hard, with 
no sensitiveness to the touch or to change of temperature, and they 
will remain so indefinitely. In case the child is so timid as to prevent 
this course, dry the cavity, take out as much softened dentin as the 
patient will permit, carry the crystals on softened gutta-percha into 
the cavity and pack it, leaving it until such time as desirable to make 
a more thorough operation." 

In the writer's opinion it is better to open proximal cavities from 
the occlusal surface rather than make V-shaped spaces, as the full 
diameter of the teeth should be left to preserve the fulness of the arch. 

Silver nitrate in its action penetrates but a short distance. 



FILLING MATERIALS 

Gutta-percha. — Pink base-plate gutta-percha is a most valuable 
filling material. In proximal cavities where it is not exposed to wear 
and where the shape of the cavity is such as to retain it, it is prac- 
tically indestructible. In occlusal and compound cavities in which it 
is exposed to wear it has wonderful durability, lasting in some cases 
for several years. 

Directions for Use. — Cut the gutta-percha in small pieces and place 
them on a gutta-percha warmer, where they can be kept soft but not 
heated enough to injure the material. The instruments also should 
be warmed. 

Occlusal Cavities. — Cut away the margins of thin enamel with 
suitably shaped chisels, and remove the decayed and softened dentin 
with spoon and hatchet excavators. Do this as thoroughly as the 
patient will permit, but do not sacrifice the patient to thoroughness, for 
the thorough removal of softened dentin is not as essential with the 
deciduous as with permanent teeth, because the gutta-percha is, by 
mastication, kept in such accurate contact with all the walls of the 
cavity that further softening will go on very slowly if -at all. No special 

1 Dental Cosmos, 1892, p. 982. 



FILLING MATERIALS 671 

attention need be paid to the form of the cavity, except that its mouth 
should not be larger than the interior, nor should any parts of the cavity 
be inaccessible to the filling material. After excavating, dry the cavity 
with bibulous paper, and apply campho-phenique, oil of cloves, or 
carbolic acid, to sterilize any softened dentin which may not have been 
removed. For drying cavities, prepare paper cylinders, of different 
sizes, as follows : Tear the bibulous paper in strips from half an inch to 
two inches in width. Roll or twist each of these strips into a rope, 
but not too tightly — just enough to retain the shape. Cut these ropes 
into cylinders from a quarter to half an inch in length. Some of these 
will be as large around as a lead pencil and others no larger than the 
lead itself. 

Protect the tooth from moisture as well as possible. For lower 
cavities fold a small napkin diagonally from the corner until it is about 
half an inch wide. Put the end of this between the gum of the upper 
canine and the lip and extend the napkin back between the upper 
molars and the cheek beyond the last tooth, then down behind the last 
lower molar, and press it between the lower teeth and tongue. Tell 
the patient to raise the tongue as it is applied, then to lower the tongue 
and hold the napkin with it. The part of the napkin between the upper 
teeth and the cheek will cover the mouth of the duct of Steno, and 
prevent or absorb the flow of saliva. It is better to cover the mouth 
of this duct with a piece of spunk about half an inch in diameter before 
applying the napkin. The folds of napkin between the lower teeth and 
tongue and under the tongue will absorb the saliva from the sub- 
maxillary glands. This part of the napkin can be held in place with 
a mouth mirror or other blunt instrument, by the operator or assis- 
tant. After applying the napkin use a large bibulous paper cylinder 
to absorb the moisture from the tooth to be filled and also from con- 
tiguous ones. With smaller cylinders or pellets dry the cavity. Apply 
once more campho-phenique or other medicament, and absorb the 
excess. 

The gutta-percha having been meanwhile warmed and softened, 
pick up a small piece of it with a cold round-pointed instrument and 
press it into the cavity. If the cavity is not large, a single piece of 
gutta-percha of a diameter less than that of the cavity, but longer 
than the cavity is deep, can be pressed in quickly and at one move- 
ment. For medium-sized cavities select a piece of gutta-percha large 
enough to cover the floor of the cavity and press it into place with 
a cold instrument, as a warm instrument might drag it from its place. 
Add similar pieces, pressing each one to the place in which it is to 
remain, until the cavity is full. If at any time the gutta-percha in the 
cavity becomes so hard as to lose its plasticity, apply a warm instru- 
ment to soften the surface, so that the next piece will adhere to the others. 
As the filling nears completion select a small piece for the last, just 



672 MANAGEMENT OF THE DECIDUOUS TEETH 

large enough to complete the filling and no more, so that none will 
have to be trimmed away, for in trimming the surplus away the filling 
may be drawn from contact with the walls of the cavity. 

In filling large cavities it may be necessary to hold the first piece in 
position with another instrument until sufficient material is added for 
self-retention. At the completion of the filling slight pressure with a 
warm instrument should be made in such a manner as to force the 
material against all the margins of the cavity. 

Proximal Cavities. — Where possible, proximal cavities should be 
opened from the buccal surfaces, as advised by Dr. Bonwill, as in 
such cases gutta-percha fillings will not be exposed to the force of 
mastication. This plan is not often practicable because the patient 
is seldom presented till the cavity has become visible by opening 
into the occlusal surface of the tooth. In such cases cut away the 
enamel only enough to give access to the cavity, excavate the decayed 
dentin, and trim the buccal, lingual, and cervical walls until a smooth, 
firm margin is obtained. 

In filling such a cavity use small pieces of softened gutta-percha, 
pressing each piece where it is to remain, and avoid a surplus. Press 
the gutta-percha against the adjoining tooth as if it were a matrix or a 
fourth wall of the cavity and let it remain. It is useless to trim it 
away from the adjoining tooth, because the force of mastication would 
soon spread the filling against it again. 

If a proximal cavity cannot be readily shaped so that it will retain 
the gutta-percha, it may be packed against the adjoining tooth, as 
if it were an occlusal cavity. It will prevent decay, especially if silver 
nitrate is applied, as already described, and may be retained until the 
patient is older, when a more thorough operation may be performed. 

The spreading of the gutta-percha by the force of mastication will 
tend to separate the teeth — which is sometimes an advantage; and also 
to press upon the gum in the interproximal space — which is a disad- 
vantage. In filling children's teeth we cannot always reach the ideal, 
but must select the method and material which will have the greatest 
advantage with the least disadvantage. If the teeth separate so much 
that the pressure of the gutta-percha upon the gum tissue becomes a 
serious annoyance, some other material must be substituted. 

To prevent the impinging of the gutta-percha upon the gum in the 
interproximal space, Dr. M. W. Hollingsworth 1 has invented a space 
guard, consisting of a concave elliptical piece of metal coated on the 
convex surface with gutta-percha. This guard is to bridge over the 
interproximal space. It is placed in position with the instrument 
shown in b, Fig. 700, which is warmed slightly, so that the point can 
enter a small hole in the guard and adhere to the gutta-percha on the 

1 Dental Cosmos, 1896, vol. xxxviii, p. 553. 



FILLING MATERIALS 



673 



under side, as shown at c. The guard is placed in the cavities, after 
warming the gutta-percha, as shown in Fig. 701, and thus covers the 
cervical borders. Gutta-percha is now filled in over the guard as if 
the two cavities formed a single crown cavity. 



Fig. 700 



Fig. 701 








Advantages of Gutta-percha. — It is easily applied to the cavity; it is 
insoluble; is durable even when masticated upon; is a non-conductor of 
thermal impulses; the filling is finished as soon as the cavity is full; it 
spreads under the force of mastication, and is thus kept in contact with 
the walls of a cavity; it can be used even under moisture. 

Disadvantages. — Gutta-percha is softer than other filling materials, 
and hence wears away more rapidly. In proximal cavities it will 
spread the teeth apart, and may then press upon and irritate the gum. 

Dryness of the cavity, though very desirable, is not absolutely 
necessary. 

Advantage of Zinc Phosphate Cement. — It is a poor conductor of 
heat; it withstands the force of mastication better than gutta-percha; 
it adheres to the walls of the cavity, and hence will remain where no 
other material can; it is easily applied; its color may be selected to 
match the tooth. 

Ames' copper cement seems to be even a better preservative than zinc 
cements in places where the black color is not objectionable. 

Disadvantages. — Absolute dryness of the cavity is a prerequisite to 
its success; it must be kept dry for several minutes after it is inserted 
in the cavity. Zinc phosphate cement disintegrates in some mouths 
much more rapidly than in others. If placed too near the pulp it may 
by chemical irritation devitalize it. 

Application of the Rubber Dam, — While many hesitate to attempt 
the use of the rubber dam with children, it will be found upon trial that 
most of them will submit to it without trouble, and many will prefer it 
to other means of keeping cavities dry. 
43 



674 MANAGEMENT OF THE DECIDUOUS TEETH 

Although there is an advantage in applying the rubber dam before 
excavating — because dryness makes the teeth less sensitive, and a clearer 
view of the cavity is obtained — still, for the sake of not tiring the little 
patients by too long restraint in one position, it is better to do most of 
the excavating before its application. 

The small size of the necks of the deciduous teeth compared with 
that of the crowns renders the retention of the rubber dam easier than 
with permanent teeth. Even considering the smallness of the patients' 
mouths, the application of the rubber dam is not difficult in many 
cases. 

For retaining the rubber dam on the second molar a clamp will 
sometimes be necessary, but for the other deciduous teeth a floss silk 
ligature will be sufficient. Having punched holes of suitable size 
through the rubber dam, apply it over the teeth affected. If the cavity 
is in the occlusal or buccal surface only, it will not be necessary to 
apply it over more than one tooth; but if the cavity is in the proximal 
surface it will be necessary to apply the rubber dam over two or some- 
times three teeth, or even more, if several cavities are to be filled at 
one sitting. 

It is not always necessary to tie a ligature around the neck of the 
tooth, as merely passing the waxed floss silk between the teeth will 
often force the rubber around the neck of the tooth enough to retain it 
even above a proximal cavity. The silk may then be removed by 
drawing the end through between the teeth. 

With a thin burnisher or spatula turn up the edge of the rubber 
around the neck of the tooth toward the gum. The tendency of the 
rubber then will be to slide in that direction and not over the crown. 
If a ligature be necessary to hold the rubber above the edge of a proximal 
cavity tie it tightly around the neck of the tooth, even forcing it toward 
or under the edge of the gum with an instrument when necessary. 
The clamp on a second molar may often be dispensed with after a 
ligature is applied, unless it is needed to hold the rubber out of the 
operator's way. The only object in omitting the clamp is to prevent 
pain or discomfort to the child. 

If a simple ligature will not retain the rubber on a second molar 
before the first permanent molar has appeared, its efficiency may be 
greatly increased by stringing a bead, about an eighth of an inch or less 
in diameter, on the thread and tying a simple knot in it so that the 
bead will be in about the middle of the ligature. Tie the ligature around 
the tooth so that the bead will lie against the distal surface of the 
second molar on or near the gum. This bead will prevent the rubber 
slipping off the tooth. A short cylinder of bibulous paper may be tied 
in the ligature and applied with the same effect, and even a large knot 
in the ligature on the distal surface of the tooth will often answer the 
purpose. 



FILLING MATERIALS 675 

The corners of the rubber dam should be held out of the way by a 
suitable holder extending around the head. The lower border may be 
held out of the operator's way by small weights, hooked in the edge. 

Dry the cavity and the whole tooth or teeth, and complete the 
excavation. 

Filling Cavities and Cement. — As cement can be applied easily 
in undercuts and very irregularly shaped cavities it is not necessary to 
cut away the enamel more than is sufficient to enable the operator to 
remove the disintegrated dentin thoroughly. Even the thorough re- 
moval of the latter is not as essential for a cement filling as for other 
materials, for, if the edge of the cavity can be made smooth and the 
softened dentin be thoroughly sterilized, the cement will hermetically 
seal it and prevent further disintegration until it is worn away beyond 
the sound edges. 

It must be remembered in excavating cavities in deciduous teeth 
that the pulp is much larger in proportion to the size of the crown than 
in permanent teeth, and that in trying to make undercuts or retaining 
grooves deep enough to retain a filling, the pulp may be exposed — an 
accident which should be carefully guarded against, for the deciduous 
pulp has not the recuperative power possessed by the pulp of a perma- 
nent tooth. Moreover, death of the pulp prevents normal resorp- 
tion of the root, and may thus cause irregularity of the permanent 
teeth. 

For most cases the cement should be mixed as thick as can be easily 
and quickly manipulated, but if the pulp is nearly exposed the cement 
should be used so thin that it can be applied without pressure, by 
flowing it over the floor of the cavity. Cement mixed moderately thin 
will adhere better to the walls of the cavity than when it is as thick 
as it is possible to apply it. The thinner the cement the longer time 
it will take to harden, but the thicker it is mixed the more durable it 
will be. Do not keep the little patient in a constrained position longer 
than necessary. The easier the first operation is for him the more 
readily will he return for the second. 

If the pulp is very nearly exposed apply Fletcher's carbolized resin 
over the floor of the cavity. For this purpose remove the stopper of 
the bottle until by evaporation the carbolized resin has thickened to the 
consistence of syrup. Dip a small probe in the thickened mass, so 
that a small drop will adhere to the end. This drop may be then con- 
veyed to and spread over the floor of the cavity. This will prevent 
contact of the cement with the most sensitive dentin and lessen the 
possibility of deleterious action on the pulp. 

Where it is possible to apply the rubber dam and to excavate thor- 
oughly the same excellent result with cement may be expected as when 
it is used in permanent teeth, but often it is not possible to operate as 
thoroughly. 



676 MANAGEMENT OF THE DECIDUOUS TEETH 

By applying melted paraffin 1 or sandarac varnish to the cement the 
rubber dam may be removed sooner than otherwise, and the cement 
will be protected from moisture by the coating of paraffin or varnish. 

As paraffin is insoluble in any agent that can attack it in the mouth, 
the more it is absorbed by the cement the longer it will protect it from 
everything but wear; therefore, do not be content merely to flow the 
melted paraffin over the cement, but hold a heated instrument in con- 
tact with the filling and keep the paraffin melted until all that is possible 
is absorbed. If a proximal filling has been inserted pass a very thin 
heated spatula between the cement filling and the adjoining tooth to 
make sure that the paraffin covers it to its cervical margin. 

When the rubber dam cannot be applied, cement may still be used 
with success if the cavity can be kept dry with napkins or rolls of cotton 
or spunk until it is inserted and quickly covered with melted paraffin. 

Deep cavities may be advantageously lined with cement and pro- 
tected with paraffin until the cement is hard, when the paraffin may be 
removed and gutta-percha or amalgam inserted. 

Occlusal fillings of cement can be kept dry by applying temporary 
stopping very soft as soon as the cement is put in. Gilbert's is excel- 
lent for the purpose, as it adheres to the cement. Buccal fillings, some- 
times approximal, may be protected in the same way. A thin tempo- 
rary stopping may be left to be worn away by occluding teeth. 

Cavities in Incisors. — Decay in deciduous incisors is much more 
rare than in the other teeth, and they are lost so early in child life that 
it is seldom necessary to fill them. Zinc phosphate cement is the best 
filling material for these teeth, because they are so small that it is very 
difficult to shape the cavities properly for retaining other materials. 

If it is found that cement disintegrates rapidly in proximal cavities, 
an attempt should be made to shape them so as to retain gutta-percha. 
The first filling of cement may have removed the sensitiveness suffi- 
ciently to allow deeper excavating at a subsequent sitting, or there 
may have been a deposit of secondary dentin, thus removing the pulp 
from danger of exposure in properly shaping the cavity. 

Amalgam. — While amalgam is a valuable filling material, its use 
necessitates much greater care in the preparation of cavities than is 
necessary with gutta-percha or cement, for it neither spreads under 
mastication like the former nor does it adhere to the walls of a cavity 
like the latter. The spreading of gutta-percha will stop a leak that 
would be fatal to an amalgam filling, and cement will adhere in a cavity 
from which amalgam would be easily dislodged. 

Amalgam should be used when the decay can be thoroughly exca- 
vated and the cavity prepared with strong, smooth edges, and good, 
retaining form. As amalgam is a better conductor of thermal im- 

1 Dr. Bonwill's suggestion. 



FILLING MATERIALS 677 

pulses than either of the materials before mentioned, it will not be 
tolerated so near the pulp, hence deep cavities must be lined with either 
gutta-percha or zinc phosphate. 

The large size of the pulp of deciduous teeth — greater in proportion 
than that of the permanent teeth — must not be forgotten in exca- 
vating, and often it is impossible to make suitable retaining grooves 
for amalgam without cutting dangerously near the pulp, especially in 
proximal cavities. 

The preparation of occlusal cavities is comparatively simple, as the 
enamel may be easily cut away so as to make firm edges, slightly 
bevelled, and to allow thorough excavation of softened dentin. 

The burring engine can be used to greater advantage with children 
than many would suppose. The whirring noise often distracts their 
attention from a slight pain they might otherwise notice, and the assur- 
ance that the work can be done more quickly is a great encouragement. 

In preparing proximal cavities for amalgam a free opening should 
be made in the occlusal surface and given a dovetail shape, extending 
farther upon the occlusal surface in proportion to the size of the cavity 
than in permanent teeth, because more reliance must be placed on it for 
retention than upon lateral grooves, for there is not much depth of 
dentin in which to make them. The cervical border of the cavity must 
be smooth and the floor at right angles to the long axis of the tooth. 
The lateral walls must be cut smooth and bevelled, and may be slightly 
grooved. If the cavity extend below the margin 
of the gum, the latter should be crowded away 
with a temporary stopping or by packing a tightly 
rolled pledget of cotton between the teeth and 
relying on its swelling. 

In many cases it is possible to extend a proxi- 
mal cavity to the sulcus and make a step anchorage, 

1 ° Prepared cavity showing 

aS in permanent teeth. bevelling of enamel edges. 

While the application of a rubber dam is not as *f ■ an „ d square base for 

. . filling, B. 

essential as in using cement, it is a great advantage, 
for it renders the proper preparation of the cavity more certain, but it 
need not be applied until the cavity is nearly prepared. Its use is more 
often necessary with the lower teeth than with the upper. 

Amalgam should not be mixed too dry, but should be plastic enough 
to be packed easily without crumbling. In occlusal cavities introduce a 
piece half as large as the cavity, and with a small ball burnisher spread 
it over the floor of the cavity toward the walls. Introduce other smaller 
pieces and proceed as before until the cavity is nearly full. Excess of 
mercury is thus forced to the edges of the cavity, whence it can be 
brushed away with cotton or bibulous paper. 

The last pieces of amalgam should be "wafered," as recommended 
by Prof. J. Foster Flagg — that is, squeezed in chamois skin with large 




678 MANAGEMENT OF THE DECIDUOUS TEETH 

flat-nosed pliers until as much mercury as possible is pressed out. This 
leaves the amalgam in a thin, brittle wafer, too hard for ordinary 
use. Break it up in pieces half the diameter of the cavity. Press one 
of these in the middle of the nearly completed filling. It will readily 
absorb the excess of mercury that has been worked to the surface, 
and can be spread toward the margins with a round burnisher. Other 
pieces can be burnished on until the filling is quite hard. 

In filling proximal cavities the same plan may be followed if a matrix 
of thin steel or German silver be used. In lieu of the matrix a very 
thin spatula may be held between the teeth. 

Whenever possible, fillings in deciduous molars should be given full 
contour to prevent the crowding of food between the teeth and also to 
prevent the first permanent molar from crowding them together and 
thus taking up room which will be needed by the bicuspids. 

The child should be cautioned against masticating too soon upon 
proximal fillings, although no caution is needed in case of occlusal fill- 
ings hardened by the "wafering" process. 

Tin and gold are excluded from the list of desirable filling materials 
for temporary teeth, not because they are not good filling materials, but 
because the circumstances are such that they cannot be used to advan- 
tage. Although a small gold filling may be inserted in a few minutes in 
an occlusal cavity, the insertion of a large gold filling would be inflict- 
ing a needless cruelty on a child on account of the length of time it must 
be held in one position. 

As the insertion of a tin filling is nearly if not quite as difficult and 
tedious an operation, it is open to the same objection. 



EXPOSED PULPS 

On account of the difficulty of properly capping an exposed pulp in 
a deciduous tooth, the operation should seldom be attempted. It is 
better to devitalize the pulp and remove it. 

Extirpation of the pulp may ordinarily be accomplished painlessly after 
anesthetizing it with cocain under pressure. 

If, however, for any reason, immediate extirpation under cocain 
anesthesia becomes impracticable in a given case, then resort may be 
had to the use of arsenous oxid paste as a devitalizing agent, always 
having in mind that but a minute quantity of the paste is required and 
less time is needed to effect the devitalization of a deciduous tooth 
pulp than that of a permanent tooth. Any of the numerous arsenical 
pulp-devitalizing pastes may be used in children's teeth under reason- 
able restrictions as to quantity of the drug used and length of time of 
the application. , 



EXPOSED PULPS 679 

The writer has found the following formula 1 an excellent one: 

1$ — Acidi arseniosi, 
Morphiae acetatis, 

Pulv. opii aa equal parts 

Creosoti q. s. to make paste. 

Why opium and acetate of morphine should both be used in the same 
prescription is not clear, as their properties are so nearly the same, but 
the paste has been satisfactory in devitalizing pulps with no pain, or 
with a minimum amount. Other formulae may be equally satisfactory. 

In occlusal cavities its application is simple. Excavate the softened 
dentin as thoroughly as possible without inflicting pain, using spoon- 
shaped excavators to prevent puncturing the pulp. If the excavation 
can be carried far enough to apply the paste directly to the pulp its 
action will be more rapid. Dry the cavity, apply a small amount, not 
larger than half a pinhead in size, with a small probe and cover it with 
a pellet of cotton, or place in the cavity a small pellet of cotton one 
side of which has been touched to the paste. Add enough pellets of 
dry cotton to fill the cavity, then apply a drop of sandarac varnish, 
sufficient to saturate at least half the depth of cotton. This is a better 
plan than dipping the pellets in the varnish before inserting, because an 
excess of the latter is apt to come in contact with the pulp and cause 
pain, or, penetrating between the paste and the pulp, may render the 
former inoperative. Temporary stoppings, such as Gilbert's, White's, or 
Fowler's, are excellent for sealing the cavity, but take a little more 
time than cotton and varnish. Such temporary stopping should be well 
softened by heat to prevent pressure on the pulp in its insertion. A 
good plan is to warm the end of the long stick of stopping and press 
it into the cavity, using the remainder of the stick as a handle, then 
remove the surplus and smooth with a warm instrument. 

In proximal cavities extending near to or under the margin, the gum 
should be protected, before applying the paste, as follows: 

Make, by rolling between the fingers, a cylinder of cotton as long 
as the width of the tooth and about the size of the lead of a pencil. 
Saturate it with sandarac varnish and pack it between the teeth upon 
the gum, extending part of it below the edge of the cavity, thus sealing 
this portion of the cavity and reducing it nearly to the form of an 
occlusal cavity. Paste applied in a proximal cavity so protected can- 
not flow upon the gum unless too great a quantity has been used. 
The paste should be applied and sealed as in an occlusal cavity. 

"Devitalizing fiber" is very satisfactory and may be used with less 
fear of its affecting the gum tissue. 

The paste may be allowed to remain in the cavity for from twelve 
to forty-eight hours. The possibility of the dressing being dislodged, so 

1 Used by Dr. E. N. Clarke in the "fifties." 






680 MANAGEMENT OF THE DECIDUOUS TEETH 

as to allow the paste to come in contact with the gum tissue, should 
warn one to have the patient return much sooner than when the case 
is an occlusal cavity from which it is impossible for the paste to escape. 

Much has been said about the danger of, application of arsenic in 
deciduous teeth when the roots are undergoing resorption, but the 
writer has never seen any bad effects from such use; still it must be 
admitted that the ratio of danger varies with the degree of resorption 
of the root. An examination of Prof. Peirce's diagram (Fig. 698) will 
show the average amount of resorption at different ages, and enable 
one to discriminate. The writer believes that the sensitiveness of a 
deciduous pulp varies inversely with the amount of resorption of the 
root, and that devitalization is called for in very few cases in which 
there is danger of deleterious action. 

Prof. L. L. Dunbar advises the use of aqua ammoniac for devitalizing 
the pulp of a temporary tooth, by applying it on a pledget of cotton in 
the cavity, one or two applications being sufficient in most cases. This 
plan is not open to the objections urged against the use of arsenous oxid. 

When the pulp is devitalized, open the cavity freely into the pulp 
chamber and apply on cotton glycerite of tannic acid. Leave this 
about a week, by which time the pulp tissue will have become so 
hardened by the tannin that it may be removed much more readily 
than without such treatment. 

The application of mummifying paste is advised by many, after 
devitalization, to avoid the necessity of removing the pulp. If a real 
mummifying paste can be found, its application will be the ideal treat- 
ment, but experience has demonstrated that the use of those thus far 
proposed is less satisfactory than the practice of radical removal of 
the pulp tissue and obliteration of the chamber and canals by a suitable 
filling material. , 

FILLING PULP CANALS 

In the pulp canals apply iodoform paste made by mixing iodoform 
with oil of cassia and glycerol to such a consistence that it can be readily 
applied on a probe. 

Fill the pulp chamber with. " temporary stopping" or gutta-percha, 
and the cavity with cement, gutta-percha, or amalgam, according to 
indications. 

If the tooth be very frail, fill the cavity with cement, because, owing 
to its adhesive properties, it strengthens the tooth. If the cavity be 
proximal and it is desirable to wedge the teeth apart, use pink gutta- 
percha. 

If the walls be strong and some time will elapse before the natural 
exfoliation of the tooth will occur, fill with amalgam. 

If absorption of the roots occurs, the iodoform in the canals will not 
interfere. 



ALVEOLAR ABSCESS 681 

Salol, which was advocated as a root filling for permanent teeth by 
Dr. A. E. Mascort, 1 of Paris, France, is well adapted also for filling the 
canals of deciduous teeth. " It is a white crystalline powder, insoluble 
in water and glycerol, but soluble in alcohol, ether, chloroform, etc.; 
fuses at 40° C, but crystallizes quickly again." Melted together, salol 
and aristol, salol and iodoform, or salol and paraffin, become liquid 
like salol alone. After a pulp canal is thoroughly dried the salol may 
be fused on a small spatula and carried to the canal, into which it will 
be taken by capillary attraction, or a broach may be heated and inserted 
in the salol. A small quantity will adhere like a drop of liquid and 
may thus be carried to the canal. The heated broach may be again 
introduced in the canal to insure thorough application. Dr. Mascort 
uses the hypodermic syringe with a small needle for introducing into 
the canals. It will crystallize in a very short time, making a solid filling. 



ALVEOLAR ABSCESS 

The treatment, as with the permanent teeth, consists in removal of 
the cause, i. e., almost invariably, a decomposed pulp. Even here an 
abscess seldom occurs if there be any opening from the cavity of decay 
to the pulp chamber, unless a foreign substance has stopped this opening. 

Make a free opening into the pulp chamber and with a syringe 
wash out as much of the contents as possible. Dry the chamber and 
apply a dressing of formo-cresol (Buckley) or formo-phenol, the former 
consisting of equal parts formalin and tricresol, the latter of equal parts 
phenol and formalin. The dressing should be sealed in with a porous 
dressing seal, such as cotton saturated with carbolized resin or a thick 
solution of aristol in chloroform and the case dismissed until all inflam- 
matory symptoms have subsided, when the roots may be filled with 
iodoform paste and a permanent filling inserted in the carious cavity. 

If a fistulous opening has formed through the outer alveolar plate, 
but not through the gum, an opening should be made through the latter 
with a sharp lancet about five minutes after the application of 4 per 
cent, cocain hydfochlorid solution on a wad of cotton. 

If a mild antiseptic solution such as electrozone or 1 per cent, potas- 
sium permanganate can be forced from the pulp chamber through 
the root canals and fistulous opening, the accumulated pus will be 
thoroughly evacuated and the cure hastened. As a rule, however, the 
abscess disappears after the cause is removed, that is, the putrescent or 
decomposed contents of the pulp chamber and canals. 

After drying the pulp chamber and canals, apply iodoform paste 
therein and seal the cavity for a few days with temporary stopping. 

1 Dental Cosmos, 1894, p. 352. 



682 MANAGEMENT OF THE DECIDUOUS TEETH 

When the inflammation of the pericementum has disappeared the pulp 
chamber and canals may be filled as before directed. 

Often the inflammation of the pericementum will be so great, or in 
popular expression the tooth so "sore" to the touch, when the case is 
presented that at the first sitting nothing more can be done than to 
make an opening into the pulp chamber to allow the escape of pus or 
gases of decomposition. This relieves the pain, and manipulation and 
treatment may be left until the inflammation has subsided. 

PROPHYLACTIC TREATMENT 

This lies more in the hands of the parent than of the practitioner, but 
should be strongly urged by the latter upon the former. The nurse 
or parent should begin early to clean the child's teeth by means of a 
cloth wrapped around the finger. If the teeth cannot be kept clean in 
this manner a small brush should be used, especially after eruption of 
the molars. Floss silk should be used daily between the teeth. One end 
of the silk should be held in each hand so as. to pass over the end of 
each index finger and be made taut between them. This taut part 
can be pressed down between the teeth and passed up and down against 
the proximal surface of each tooth, then one end of the thread should 
be released and pulled through the interdental space. 
I This will drag out any particles of food that may be there, and is 
much better than the toothpick for the purpose. If particles of meat 
or other food have lodged so firmly that the plain waxed silk will not 
dislodge them, tie a single knot in the thread and pull that through. 
: This cleansing with the cloth, brush, and silk should be done before 
the child retires at night, for that is the "period of decay." The parts 
are at rest longer than at any other time, and the fluids of the mouth 
are not kept in circulation between the teeth by means of the tongue, 
lips, and cheeks. Theoretically the teeth should be thus thoroughly 
cleaned after each meal, but "satiety breeds disgust," and it is not 
best to insist on more than will probably be accomplished. 

Children will soon learn to use the brush and floss silk themselves, 
and finding the mouth much more comfortable when ""clean," they will 
endeavor to keep it so. Many a child has been denied candy for years 
from the belief that "sweets decay the teeth," but parents may be 
assured that no harm will be done by the moderate use of pure candy 
if the "sweet" is not allowed to remain between and around the teeth 
until it becomes acid, and that may be prevented by cleansing the teeth 
after the candy or sugar is eaten. _ A child may be taught cleanliness in 
this manner who would be only taught rebellion by the repeated denial 
of sweets, the reasons of which he cannot understand. 

Prophylactic mouth washes should be used — such as Listerine diluted 
to a 10 per cent, solution. 



CHAPTER XXI 

ORTHODONTIA 

By EDWARD H. ANGLE, M.D., D.D.S. 

OCCLUSION 

"Substantial progress in any science is impossible in the absence of a 
working hypothesis which is universal in its application to the phenomena 
pertaining to the subject-matter. Indeed, until such a hypothesis is 
discovered and formulated, no subject of human investigation can 
properly be said to be within the domain of the exact sciences. It 
enables one skilled in the science to practise it with a certainty of 
results in exact proportion to his knowledge of its principles and skill 
in applying them to the work in hand." — Hudson. 

Orthodontia 1 is the science of occlusion of the teeth and the art of 
correcting malocclusion. 

Occlusion is the basis of the science of orthodontia. The shapes of 
the cusps, crowns, and roots, and even the very structural material of 
the teeth and their attachments, are all designed for the purpose 
of making occlusion the one grand object, in order that they may best 
serve the chief purpose for which they were intended, namely, the 
cutting and grinding of food. We will define occlusion as being the 
normal relations of the occlusal inclined planes of the teeth when the jaws 
are closed. 

Malocclusion of the teeth is but the perversion of their normal relations. 
It can be studied intelligently only from the basis of the normal, and 
to begin its study without first being familiar with the normal would 
be as unfruitful as the study of the pathology of any other of the struc- 
tures of the body without first mastering their anatomy and physiology. 

There must be, then, clearly fixed in the mind of the student of ortho- 
dontia not only Nature's plan of the normal denture when complete, 
but also of its beginnings — the growth and development of parts, and 
their co-relations. 

The normal human denture in its completeness includes not only the 
jaws, alveolar process, dental arches, and especially the teeth and peri- 
dental membrane, which to the orthodontist are of prime importance, 
since on them chiefly his operations are performed, but also the muscles 

1 From the Greek, op66g } straight ; odovg, tooth. 

(683) 



684 ORTHODONTIA 

of lips, cheeks, tongue, and mouth, the nasal passages, palate, and 
throat, as these assist the teeth in performing their functions. They 
are also powerful factors in establishing and maintaining either har- 
mony or inharmony in the development and arrangement of the teeth, 
and this just in proportion as they are, singly or collectively, normal 
or abnormal in their own development and functions. 

It is, of course, not within the province of a brief treatise on 
orthodontia to teach as minutely and thoroughly as is necessary to 
a complete understanding thereof, the embryology, histology, and 
anatomy of the human denture. The student is therefore strongly 
recommended to their study elsewhere, and especially to the works 
of Drs. Noyes, Black, Broomell, Cryer, and Kyle. A thorough 
knowledge of the individual teeth is of such inestimable value to the 
orthodontist that the student is urged to carve, or model in clay, the 
different tooth forms, as in no other way will there be such a vivid 
impression stamped upon his mind of the correct outlines of their crowns 
and the positions and relative proportions of their cusps, together with 
their marginal, triangular, and oblique ridges, their grooves and sulci, 
and their proper relations to the teeth of their own arch and to those of 
the opposing arch. 

Nature in building the dental apparatus requires a long period of 
time — twenty years or more — and from the beginning of the formation 
of the dental follicle and the tissues that support and precede it, to the 
eruption of the last third molar, she works in accordance with a definite 
plan toward a definite end, viz., the production of a type that has been 
the type of man's denture as long as man has been man. 

By referring to Figs. 703 and 704, which represent the teeth in normal 
occlusion, it will be seen that each dental arch describes a graceful 
curve, and that the teeth in these arches are so arranged as to be in 
greatest harmony with their fellows in the same arch, as well as with 
those in the opposite arch. 

In their normal relations the external curve of the lower arch is 
slightly smaller than that of the upper, so that in occlusion the labial 
and buccal surfaces of the teeth of the upper jaw slightly overhang 
those of the lower. 

The mesio-buccal cusp of the upper first molar is received in the 
buccal groove of the lower first molar. The teeth posterior to the first 
molars engage with their antagonists in a precisely similar way; those 
anterior to the first molars interlock with one another in the interspaces 
until the incisors are reached ; of these, the upper usually overhang the 
lower about one third the length of their crowns, although the length of 
overbite varies according to the typal pattern of the teeth. 

The upper central incisor being broader than the lower, it necessarily 
extends beyond it distally, overlapping in addition about one-half of 
the lower lateral incisor; the upper lateral occludes with the remaining 



OCCLUSION 



685 



Fig. 703 




Typical occlusion. (Cryer.) 



Fig. 704. 




Normal occlusion. 



686 



ORTHODONTIA 



portion of this tooth and with the mesial incline of the lower canine ; the 
mesial incline of the upper canine occludes with the distal incline of the 
lower canine, the distal incline of the upper occluding with the mesial 
incline of the buccal cusp of the lower first premolar. In the same 
order the series of buccal cusps of the premolars occlude — the mesial 
incline of each upper occluding with the distal incline of the correspond- 
ing lower tooth. 

The distal incline of the buccal cusp of the second upper premolar 
occludes with the mesial incline of the mesio-buccal cusp of the lower 
first molar. The mesial incline of the mesio-buccal cusp of the upper first 
molar occludes with the distal incline of the mesio-buccal cusp of the 
lower first molar; the distal incline of the mesio-buccal cusp of the upper 



Fig. 705 




Normal occlusion. 



first molar occludes with the mesial incline of the disto-buccal cusp 
of the lower first molar; the mesial incline of the disto-buccal cusp of 
the upper first molar occludes with the distal incline of the disto-buccal 
cusp of the lower first molar, and the distal incline of the disto-buccal cusp 
of the upper first molar occludes with the mesial incline of the mesio- 
buccal cusp of the lower second molar. This same order is continued 
with the buccal cusps of the second and third upper molars, the distal 
incline of the disto-buccal cusp of the upper third molar having no 
occlusion. 
It will thus be seen that each of the teeth in both jaws has two antag- 



OCCLUSION 687 

onists or supports in the opposite jaw, except the lower central incisor 
and upper third molar. 

As the inclined planes match and harmonize most perfectly in the 
bucco-occlusal relations of the teeth, so there is a similar arrangement 
in their linguo-occlusal relations, except that the lingual cusps of the 
lower premolars and molars project beyond those of the upper teeth 
into the oral space, as shown in Fig. 705. 

Likewise, in the transverse arrangement, the buccal cusps of the lower 
molars and premolars rest between the buccal and lingual cusps of the 
upper molars and premolars, and the lingual cusps of the upper molars 
and premolars rest between the buccal and lingual cusps of the lower 
molars and oremolars, as in Fig. 706. 

Fig. 706 




Typical occlusion of molars; transverse view. (Oyer.) 

The grinding surfaces are thus enormously increased in extent and 
efficiency over what would be possible if they consisted of a single row 
of cusps or of plane surfaces. 

But increase of masticating surface is not the only reason for this 
complex interdigitation of the cusps and inclined planes of the teeth, it 
is likewise of great importance in providing for the teeth a mutual 
support. 

The sizes, forms, interdigitating surfaces, and positions of the teeth 
in the arches are such as to give to one another, singly and collectively, 
the greatest possible support in all directions. 

This is the pattern, the form, the type of the normal in occlusion — 
the normal denture. 

In the normal building of the human denture, nature works toward a 
definite end to produce the most efficient parts with the most efficient 
arrangement of these parts that they may in function be most efficient. 
Each tooth is not only in harmonious relation with every other tooth, but 
helps to maintain every other tooth in these harmonious relations, for 



688 ORTHODONTIA 

the cusps interlock and each inclined occlusal piane serves to prevent 
each tooth from sliding out of position, and further, to wedge it into posi- 
tion if but slightly malposed, that is, if not beyond the normal influence 
of the inclined planes. 

A careful study of the relations of the inclined occlusal planes and 
the marginal, triangular, and oblique ridges, in connection with the 
movements of the jaw, cannot fail to impress thoughtful persons not 
only with the influence which these exert in maintaining each individual 
tooth in correct position, but as well their wonderful efficiency for incising 
and triturating the food required by omnivorous man, and with their 
marvellous forms and arrangement for self-cleansing and consequent 
self-preservation. So perfect is the plan in the relations of the teeth as 
a whole that each cusp or part of a cusp contributes perfectly to the 
balance, harmony, and efficiency of all, and consequently the mesio- 
distal diameter of a tooth, or any portion of it, cannot be sacrificed 
without proportionately disturbing the delicate balance and integrity of 
form and function of the whole. To one versed in occlusion no argument 
is needed to impress the importance of the complete and perfect restora- 
tion to contour of missing portions of teeth, or of the adjustment to normal 
position of those teeth that are malposed. 

Not only are the individual tooth patterns and the relations of the teeth 
most perfectly designed for performing their functions, but probably 
no other forms or relations could produce so beautiful and artistic an 
effect as an individual feature, or give so much of beauty in lines and 
expression to the face. The denture, with the teeth in normal occlusion, 
is a marked element of beauty to any face, however imperfect in other 
respects. 

There is great harmony in the lines of the teeth, although all vary, 
the result being most pleasing. How the beauty of the central incisor 
would be impaired if its mesial lines were the same as its distal lines. 
How much less pleasing would be the result if the lateral incisor were 
of the same size as the central, or even of the same pattern, instead of 
possessing the majesty of a pattern and proportionate size of its own. It is 
like the central, yet how beautiful in its difference. The canine, although 
resembling both central and lateral, adds much beauty to the whole 
in the lines peculiar to its own pattern, and how much the general effect 
is enhanced by the lateral incisor being shorter and slightly less prom- 
inent in the line of occlusion than either the central or canine. In 
orthodontic operations, or in unanatomically fashioned dentures, when 
the lateral is made prominent or of the same length as the other teeth, the 
result is pronouncedly unpleasing. Again, how unpleasing is the effect 
when these beautiful lines are impaired by grinding any of the marginal 
surfaces — a fact that should lend caution to the hand of both orthodontist 
and dentist. 



OCCLUSION 689 

Key to Occlusion. — According to nature's plan of the human denture 
all of the teeth are essential, yet in function and influence some are of 
greater importance than others, the most important of all being the first 
permanent molars. They are the largest of the teeth and the firmest 
in their attachment, which, together with their location in the arches, 
makes them the most important of all the teeth in the function of masti- 
cation. By the lengths of their crowns they also determine the extent 
of separation of the jaws and length of bite, and in this, as well as in 
many other ways, are factors in the artistic proportions of the face. 
Being the first of the permanent teeth to take their positions in the arches, 
they exercise great control over the positions w r hich the other permanent 
teeth anterior and posterior to them shall occupy as they erupt at their 
respective periods and take their respective positions in the arches. 
As they are already developed and firmly attached in the alveolar process 
when the other permanent teeth appear, the latter are built into the 
dental apparatus around them, as it were. They are not only the 
most constant in the time of taking their positions, but by far the most 
constant in taking their normal positions, especially the upper first 
molars. 

A better understanding of the reason why these teeth take correct 
positions is gained if we will but remember that theirs are the first 
permanent tooth germs formed, and also that they are the first of the 
permanent teeth to develop and erupt, which they do, unhampered, 
immediately posterior to the twenty teeth comprising the deciduous 
set, and that the deciduous teeth are free to erupt normally according 
to nature's plan, under the most favorable conditions, and do so 
nearly always in normal occlusion and in perfect accordance with the 
requirements for harmony and beauty of the developing child's face. 
So the permanent molars in erupting are not only unhampered in taking 
their positions, but, on the contrary, they are, as it were, guided into 
and guarded in correct positions by the usually normal child denture 
anterior to them (Fig. 707), and by their normal locking on eruption 
is made possible the normal eruption and locking of all the other 
teeth both anterior and posterior to them in both lateral halves of 
each arch. 

So important is the influence of these teeth in the building of the 
dental apparatus that we believe nature exercises the greatest care in 
locating them in the line of occlusion, especially the upper first molars 1 — 
which we call the keys to occlusion — and so places them that the rest of 
the dental apparatus may be completed normally, and if completed 
normally and in harmony with these teeth, the dental apparatus will 
be in best balance and harmony with the skull and the other essential 



1 Angle, "The Upper First Permanent Molar as a Basis of Diagnosis," Items of 
Interest, June 1906. 
44 



690 



ORTHODONTIA 



organs, as the eyes, the ears, the nose, etc. — indeed, with the structural 
type of the individual throughout, 



Fig. 707 




Normal denture of child. 



The fact that the upper first permanent molar varies considerably 
mesially or distally as to its location in different individuals, which is 
always noted in anything like an extensive study of the subject, has 



OCCLUSION 691 

led superficial students to regard these positions as abnormal, taken by 
chance, and often out of harmony with other principles in the anatomy 
of individuals, but in reality these variations are to be expected, and 
are necessary in the creation of different types and different individuals. 
As, for example, this molar is found to be located farther anterior in its 
relation to the skull in some of the lower orders of man and the primates 
than in the highly developed civilized man, and even in civilized man 
the mesio-distal position of this tooth may vary in each individual, yet 
this is necessary in the typal requirements. 

Theoretically the first upper molars may differ slightly in their mesio- 
distal position, even in each lateral half of the dental arches of an appar- 
ently normal individual, just as the eyes or ears may slightly differ as 
to height or location in the same person. Probably the first molars are 
never exactly constant as to the two sides, but we insist that this is but 
natural and in keeping with the rest of the anatomy, and, when slight, 
should not be regarded as an abnormality. 

And finally, that nature may err in the mesio-distal locating of these 
molars is doubtless possible, for we know the unfortunates classified as 
"freaks" are the result of her anatomical errors, but we must remember 
that freaks are very rare, and we believe that nature so very rarely 
errs in the locating of the first upper molars — the very cornerstones, as 
it were, in the foundation of the structure of an organ so essential to the 
whole physical economy as the dental apparatus — as to make it a matter 
of little or no concern to us except, possibly, in research work. The 
writer has been unable to find, after much study, a single case in an 
unmutilated denture at maturity where it would seem to him that 
nature had erred in not locating these most important teeth so as to be 
in best keeping with the other anatomical factors of the type. Indeed, 
he is also greatly impressed, after the study of a large number of cases, 
with the constancy of the normality, also, of their linguo-buccal positions, 
in accordance with the age and growth of the individual, even when 
other unfavorable influences exist, unless the teeth are forced buccally 
or lingually by locking in buccal or lingual occlusion, as in Fig. 708. 

So it will be seen that the reasons for regarding these teeth as the 
keys to occlusion are most logical and conclusive. It is, therefore, on 
their positions and the relations of their antagonists with them that the 
classification and diagnosis of malocclusion must be based. 

The first upper molars are sometimes forced to take mesial mal- 
positions temporarily, or during the growth of the denture, as a result 
of mutilation of either deciduous or permanent teeth, but this is onlv 
temporary, and the extent of their variation from normal position is 
easily determined and allowance for it made, and at maturity, or after 
the eruption of the second and third molars, it is probably rarelv, if ever, 
even in these cases, that an upper first permanent molar is found mesial 
to its correct position. This subject is further discussed in the section 
on Premature Loss of Deciduous Teeth — Etiology. 



692 



ORTHODONTIA 



Line of Occlusion. — Writers on orthodontia have long been in the 
habit of making use of an imaginary line, known as "the teeth in align- 
ment/' and "the line of the arch," from which to note regular and 
irregular alignment of the crowns of the teeth. It has most often referred 
to the general line of each individual arch, as outlined by the crowns 
of the teeth, regardless of their number or position, or of the relations 
of such lines to the skull. In this way two lines of occluson are often 
inferred, one for each arch, which may or may not have direct relation 
one to the other. In reality, as used, it has been vague and indefinite. 
So far as the writer is aware, none has comprehended its full meaning or 
importance. 

Fig. 708 




Buccal and lingual occlusion. 



That we should have a line from which to note variations from the 
normal is highly important, but that its meaning is deeper and that 
it has a far greater significance to the student of orthodontia than above 
indicated, the writer is fully convinced, and he would define the line 
of occlusion as being the line with which, in size, in form, and in 'position 
according to type, the teeth must be in harmony if in normal occlusion. 

There can be, then, but one true line of occlusion, and it is the normal 
architectural line on which the dental apparatus was designed. The 
ideal line was intended to govern not only the length, breadth, and 
peculiar curve of the dental arches, but the size and pattern of each tooth, 



OCCLUSION 



693 



cusp, and inclined plane composing these arches. And more than this: 
that as the dental apparatus is only a part of the great structure — the 
human body — each part and organ of which was fashioned according 
to lines of design, it must have been intended that the line of occlusion 
should be in harmony in form and position with, and in proper relation 
to, all other parts of the great structure, according to the inherited 
type of the individual. Hence its majesty, and according to our con- 
ception of it must be our ability to comprehend not only the art require- 
ments in each case we treat, but as well must it govern our conception 
of the requirements of the position of the teeth in occlusion and the 
various operations in treatment. The line of occlusion, then, is more 
than the tangible or material. It may be regarded as the basic ideal of 
the dental apparatus, the comprehension and appreciation of which 
will grow in proportion as our knowledge of the science of occlusion 
unfolds. 



Fig. 709 




Bonwill diagram. 



We may speak of moving a tooth of the lower arch into the line of 
occlusion, or of moving a tooth of the upper arch into the line of 
occlusion, but it must always be remembered that there can be but 
one true line of occlusion, or the line with which each tooth must be 
in perfect harmony if in normal occlusion. 

It was long ago suggested by Dr. Bonwill, and very recently by 
others, that the well-known "Bonwill law," so called, could be made 
use of in predetermining the form and position of the line of occlusion 
in cases of malocclusion, the curve and width of the arch being 
determined by the combined diameters of the upper central and lateral 
incisors and canine on one side, as per the familiar diagram shown in 
Fig. 709. 

The absurdity of this proposition is easily made apparent when we 



694 ORTHODONTIA 

remember that this would necessitate the same form of arch for every 
individual possessing the same diameter of incisors and canines, jointly, 
regardless of the demands of the facial type, when we know that in 
reality the width and form of the arch must vary, regardless of the width 
of the incisors and canines, according to the demands of the type. 
This is strikingly illustrated by the four skulls shown in Fig. 710. It 
will be seen that two of the arches are broad and short and the other 
two long and narrow, notwithstanding the fact that the diameters of 
incisors and canines may have been equal in all four cases. 



Fig. 710 











But by further study of these skulls it will be seen that each arch is 
in fine conformity with the demands of the architectural lines of the skull 
to which it belongs. The extremely broad and short arches are in 
perfect balance with the very broad and short skulls, while the long, 
narrow arches are also exactly in keeping with the extremely long and 
narrow skulls, and the patterns of the teeth are in like manner in perfect 
accord with the architectural demands of not only the skulls to which 
they belong, but to every portion of them. To make this point clear — 
if the face and skull are long and narrow, the dental arch will be long 
and narrow, and the body throughout will have the same typal charac- 
teristics. 

If the face and skull are round, the dental arch will be propor- 
tionately round and broad, and the incisors and cuspids will conform 
more nearly to the arc of a true circle, and the rest of the body will be of 
a corresponding type. While with a type of face and skull more nearly 
approximating a cube, the dental arch and all the rest of the body will 
be found to correspond, and this same harmony and balance between 
dental arch, face, skull, and the rest of the body will also hold true with all 
individuals of whatever race who represent all the degrees and variations 
between these pronounced types. The writer believes this is a typal law, 1 

1 The writer first called attention to this law in a paper read before the American 
Society of Orthodontists, September 29, 1905. See Items of Interest, June, 1906. 



OCCLUSION 695 

having few, if any, variations, which anyone can verify by the study of 
skulls or of individuals. 

As there can be no fixed rules of measurement for predetermining 
the proper form of the line of occlusion in cases of malocclusion, any 
more than there can be fixed rules for determining the typal balance of 
the facial lines, for which artists have so long striven in vain, it seems 
to the writer that the best the orthodontist can do is to secure normal 
relations of the teeth and a typal form of the arch as nearly correct as he 
is able to determine, leaving the finer adjustment of this form to be 
worked out by nature through her forces governing occlusion, which 
must, it any event, finally triumph. 

Forces Governing Normal Occlusion. — As we have already seen, the 
inclined planes of the cusps of the teeth play an important part in 
maintaining normal occlusion. They also exercise the most powerful 
influence in directing the positions of the teeth during their eruption. 

When the teeth first emerge from the gums their considerable dis- 
placement is often noticeable, but this need occasion no uneasiness, 
provided, as eruption progresses, their cusps pass under the influence of 
normally placed opposing cusps. But if they pass beyond this influence 
into abnormal relations, they will not only be further deflected from their 
own proper positions, but may displace the opposing teeth and those 
subsequently to erupt as well, even to the extent of the disarrangement 
of the entire thirty-two teeth, as is possible from the mal-locking of the 
first permanent molars. So there may be times when the dividing line 
between harmony and inharmony is very slight, hence the importance 
of careful attention during the important period covering the eruption 
of the permanent teeth, especially the beginnings. 

Harmony between the complete upper and lower arches is also power- 
fully promoted by their normal action and reaction upon each other 
through the teeth. As the teeth of the lower arch erupt before their 
antagonists of the upper arch, and are consequently to an extent fixed 
in their positions before the latter appear, it follows that the lower arch 
is the form over which the upper is moulded. In other words, the lower 
arch exerts a modifying influence on the form of the upper. Of course, 
the upper reacts upon the lower, but it is unquestionable, in the writer's 
opinion, that the lower arch is the more important factor in determining 
the form of the dental arches than the upper, as has formerly been taught. 

From what has been said it may be readily seen how greatly each arch 
contributes to the other in maintaining its form and size when the 
teeth are in normal occlusion, and how pressure abnormally exerted 
on any tooth or teeth would be, resisted by all the other teeth. For 
example, pressure exerted on the labial surfaces of the upper incisors 
would be resisted not only by all the upper teeth acting as blocks of 
stone do in an arch of masonry, but also by the teeth of the lower arch 
acting through occlusion. 



696 



ORTHODONTIA 



Inversely, then, one arch cannot be altered in shape without modi- 
fying that of the other, nor can it be altered in size without soon exer- 
cising a marked effect on the other. 

The normal positions of the teeth and the normal sizes and relations 
of the arches are further powerfully influenced by another force, namely, 
muscular pressure, the tongue acting upon the inside and the lips and 
cheeks upon the outside of the arches. The latter, if normal in develop- 
ment and function, serve to keep the arches from spreading, as do hoops 
upon the staves of a cask; the former prevents too great encroachment 
upon the oral space, and each, if normal in function, contributes in like 
proportion to the harmony of balance. The upper lip will be found 
to rest evenly in contact with the gums and upper three-fourths of the 
labial surfaces of the upper incisors, leaving, however, about one-fourth 



Fig. 711 




of the occlusal ends of the central incisors and laterals to be covered 
by the edge of the lower lip, so that normally there is a restraining 
force exerted upon the upper incisors by both upper and lower 
lips. 

This force is exerted automatically in response to almost every emotion, 
and results in maintaining the teeth in harmony with the graceful and 
beautiful curve of the normal individual arch. This muscular pressure is 
far more important than is generally recognized. 

Fig. 711 represents the teeth of a child, aged eight years, where the 
jaws and teeth are developing normally. It will be noted that all of the 
permanent lower incisors have erupted and occupy their normal positions 
in the line of occlusion, each occupying its full mesio-distal space in the 
arch, compelling the lower canines to occupy positions the requisite dis- 
tance apart. Of special importance is the influence that these teeth 



OCCLUSION 697 

exercise on the opposing deciduous canines through their inclined planes, 
each blow that the upper canines receive from the lower tending to widen 
the upper arch, or at least to prevent it from becoming narrower through 
the pressure of the lips. 

So it will be seen that normal occlusion of the teeth is maintained, 
first, by harmony in the sizes and relations of the dental arches through 
the interdependence and mutual support of the occlusal inclined planes of 
the teeth; and secondly, by the influence of the muscles labially, buccally, 
and lingually. Of course, there are other forces in the normal building 
and maintaining of the dental apparatus, such as structural growth 
of all the various bones and tissues, the influence of co-related organs, 
air pressure and mental influences, all, if normal, contributing to the 
perfect balance and integrity of the whole. It is needless to say that such 
normality would only be possible with normal balance of all of the 
forces governing growth and occlusion. 

Forces Governing Malocclusion. — In beginning the consideration of 
malocclusion, let us remember that it is but the perversion of the normal 
growth and development of the denture — the side-tracking, as it were, of 
nature in some of her normal processes of building, and we would repeat 
and insist that before anyone can intelligently comprehend malocclusion, 
he must have as a basis from which to reason in determining its extent 
and complexity, a thorough knowledge not only of the normal growth 
and development of the dental apparatus, but that of the co-related 
organs and also a knowledge of their functions and interdependence. 

We know that every case has a simple beginning in its variation from 
the normal, and that very often a single tooth, from slight cause, being 
deflected from the normal, may and usually does ultimately involve 
others. The dividing line, then, between the normal and the abnormal 
in the beginning is very slight, but always clearly defined, so the normal 
in occlusion is the only logical basis for determining the variation there- 
from and the extent of the abnormal — malocclusion — and, as we shall 
see, the same forces that contribute to maintaining the teeth in their 
normal positions and harmony in the sizes of the arches are equally 
powerful when perverted in maintaining inharmony in the sizes and 
relations of the arches and malocclusion of the teeth. 

In a large percentage of cases of malocclusion the arches are more 
or less contracted, and as a result we find the teeth crowded and over- 
lapping. In these cases the lips serve as constant and powerful factors 
in maintaining this condition, usually acting with equal effect on both 
arches, and effectually combating any influence of the tongue or any 
inherent tendency on the part of nature toward self-correction. In 
other words, the arches, narrowed and diminished in size, are so main- 
tained by force from the lips, equal in power to that exerted for their 
normal maintenance when of normal size and relation, with the teeth 
in normal occlusion. 



698 



ORTHODONTIA 



Likewise each inclined plane of the cusps once out of harmony serves 
not only to maintain the inharmony, but to increase it, upon each closure 
of the jaw. 

It is interesting and instructive to note the result of these perverted 
forces even in very early indications of malocclusion. 



Fig. 712 




Fig. 712 illustrates a very common and familiar form of developing 
malocclusion. The case is that of a child where the four lower per- 
manent incisors are fully erupted, but one of them (the left lateral) 
has been deflected lingually (Fig. 713). Being thus deprived of the 
wedging and retaining influence of this tooth, the pressure of the lips 



Fig. 713 




has closed the space and diminished the size of the lower arch. At the 
same time pressure, principally from the lips and cheeks, aided by the 
occlusal planes of the lower deciduous molars, is gradually moulding 
the upper arch to conform to the diminished size of the lower. 

It will thus be seen how effectually the malocclusion will be main- 
tained and how hopeless it is to expect nature to correct this deformity 



OCCLUSION 699 

unaided. These perverted forces are traceable in all cases of mal- 
occlusion. 

Recognizing the potency of their influence, it must be apparent that 
cases of this kind, instead of being self-corrective, will become more and 
more complicated as time goes on and as each succeeding permanent 
tooth erupts. How absurd and unfortunate, then, is the common daily 
advice of many dentists to anxious parents to "let the teeth alone and 
nature will correct them unaided." 

In all such cases the position of the erupting permanent lower incisors 
should be guarded with zealous care, placed in correct positions, and 
maintained therein, that they may, through occlusion, assist in directing 
the teeth of the opposing arch into normal positions and be compelled 
to fulfil their important part in the full normal development of the 
alveolar process. This is the golden opportunity for beginning intelli- 
gent interference for the prevention of what might otherwise become 
complicated cases of malocclusion. This also applies with equal force 
•to any other lower tooth that may erupt into abnormal position, especially 
the lower first molars. If the lower teeth erupt in their normal positions 
either naturally or through proper treatment, the upper teeth will 
usually take their normal positions. 

For the reason previously stated, if the teeth of the lower arch be 
permitted to remain in malposition even to the slightest overlapping of 
one or more of the incisors or canines, the arch will be diminished in 
size just to that extent, and as a result of pressure of the lips there will 
be a corresponding contraction in the upper arch and some form of 
bunching of the teeth, especially in Class I. 

The influence of the lips in modifying the form of the dental arches 
is an interesting study, and almost every case of malocclusion offers 
some noticeable and varying manifestation of it. Indeed, the forces 
from perverted lip and cheek function are far more potent and frequent 
causes of malocclusion than has heretofore been recognized. This 
phase of this question will be further discussed under the sections on 
Etiology of Malocclusion and Treatment. 

The result of pressure from the tongue in exerting force upon the 
inside of the arches is also a factor, we are convinced, of great impor- 
tance in determining the form of the arches and the positions of the 
individual teeth. That when normal in s^ze, tone, and function, it 
exercises a gentle force upon the inside of the arch, which is in perfect 
harmony with the force exerted by the muscles upon the outside in 
maintaining the correct balance in muscular pressure upon the teeth, 
is well known, but when these forces are perverted, through abnormal 
size or function of the tongue, the result is most noticeable and character- 
istic in the malpositions into which the teeth are forced. This subject 
will also be further discussed in the section on Etiologv. 

The transferring of force from air pressure from the floor of the nose 



700 



ORTHODONTIA 



in nasal breathing, to the vault of the arch in mouth breathing, is doubt- 
less also a factor of much importance in the development and maintaining 
of malocclusion. 

When the teeth are in normal occlusion the influence of the inclined 
occlusal planes and the relations of the crowns and roots of the teeth 
are such that the great weight or force that each must bear in occlusion 
is in perfect balance with a line of axis common to both dental arches, 
as shown in Fig. 706, this line of axis being such that the force does 
not tend to displace either crowns or roots of the teeth either lingually 



Fig. 714 




Eye-ball 



Groove {hiatus semilunaris) 
leading to infundibulum 
Middle turbinated bone 

Middle meatus 
Antrum of Highmore 
Inferior meatus 

Inferior turbinated bone 



Buccal cavity 

Space between cheek and gum 



Molar tooth, upper jaw 



Root of molar tooth 



Inferior dental nerve 



or bucally/ mesially or distally, but instead is such as best to stimulate 
the normal growth of the jaws, palate, and nasal bones, and probably 
all other bones and tissues of the face, and best to maintain their normal 
size and harmony of relations. But when the line of stress is changed 
from the normal axis to one that is abnormal, as when all the upper 
buccal teeth are in lingual occlusion, the result is to disturb the balance 
greatly, and force the roots and crowns of the upper teeth lingually 



CLASSIFICATION OF MALOCCLUSION 



701 



and those of the lower buccally. How powerful is the force when so 
perverted is shown in the remarkable case illustrated in Fig. 708. 

By studying this picture in comparison with the one shown in Fig. 
714, it is easy to realize how greatly the normal development of the 
vault of the arch and the bones of the nose has been interfered with by 
this perversion of force. 

Another lesson is also here impressed, namely, how interdependent 
are the work of the rhinologist and that of the orthodontist, and vice 
versa, and how utterly useless for either to hope for success in the treat- 
ment of many of these cases without the assistance of the other, and 
how important that both should cooperate as early as possible in their 
work of establishing the normal forces of growth and development. 



CLASSIFICATION OF MALOCCLUSION 



Nomenclature. — All teeth found out of harmony with the line of 
occlusion may be said to occupy positions of malocclusion, and each 
tooth may occupy any of seven malpositions or their various deviations 
and combinations. 

Fig. 715 




The malpositions of teeth consist principally in the variation of the 
positions of their crowns from the normal, with usually little displace- 
ment of the apices of their roots, so that they incline at an angle more 
or less oblique from the normal. In some instances, however, there 
is some displacement of the apices as well as of the crowns, they having 



702 ORTHODONTIA 

either developed in malpositions, or, as in most instances, having been 
forced from their normal positions by mechanical influences, or the 
eruption of more powerful teeth in juxtaposition, as, for example, the 
crowding lingually of the lateral incisors by the development and eruption 
of the canines, as in Fig. 715. Yet even in such cases the displacement 
is not so great as appears, the malpositions of the crowns magnifying 
this appearance. 

A definite nomenclature is as necessary in orthodontia as in anatomy. 
The vagueness of descriptive terms often used renders them very 
inadequate. The terms for describing the various malpositions of teeth 
should be so precise as to convey at once a clear idea of the nature of 
the malocclusion to be corrected. The author therefore suggests the 
following, which, while perhaps not perfect, still seems to be a great 
improvement on common usage. 

For example, a tooth outside the line of occlusion may be said to be 
in buccal or labial occlusion; when inside this line, in lingual occlusion; 
if farther forward, or mesial, than normal, in mesial occlusion; if in the 
opposite direction, in distal occlusion; if turned on its axis it would be 
in torto-occlusion. Teeth not sufficiently elevated in their sockets would 
be in infra-occlusion, and those that occupy positions of too great eleva- 
tion, in supra-occlusion. These terms used singly or in combination will 
accurately describe the malpositions of any tooth or teeth in any case of 
maloccusion, from the simplest to the most complex, and used in con- 
nection with the writer's classification, make possible the conveying of 
a very complete picture of any given case of malocclusion in very few 
words. 

Although the number of cases of malocclusion is limitless, in no two 
do we find the arrangement of the teeth alike, even in those strikingly 
similar cases of Division 1, Class II. 

Yet, notwithstanding this endless variation, which has led to endless 
confusion in diagnosis and treatment among the old school writers 
and practitioners, as we shall see, all cases of malocclusion fall naturally 
into a very few distinct and easily recognized groups, or three great classes, 
with their divisions and subdivisions, and when so classified the extent 
of the variation from the normal in each case is easily comprehended 
and the requirements of treatment made manifest. 

The classification of malocclusion is based on the mesio-distal relations 
of the teeth, dental arches, and jaws, which depend, primarily, in the 
permanent denture, upon the positions mesio-distally assumed by the 
first permanent molars on their erupting and locking. Hence in diag- 
nosing cases of malocclusion we must consider, first, the mesio-distal 
relations of the jaws and dental arches, as indicated by the relation of 
the lower first molars with the upper first molars — the keys to occlusion, 
and secondly, the positions of the individual teeth, carefully noting their 
relations to the line of occlusion. 



CLASSIFICATIOX OF MALOCCLUSIOX 



703 



Class I, illustrated by Figs. 716 and 717, is characterized by normal 
mesio-distal relations of the jaws and dental arches, and normal locking 
of the first molars; that is, mesio-distally. One or even all of the molars 
may be in buccal or lingual occlusion, but this is only an incident and 
may occur in any class, and is not constant in, nor a characteristic 
peculiar to, any particular class. 

In this class the malocclusion ranges from the slightest overlapping 
of a single tooth to the most complex derangement, involving the posi- 
tions of all of the teeth in both arches, as in Fig. 872. In the average 
case (Figs. 716 and 717), however, the arches are more or less shortened 
and reduced in size, with a corresponding crowding of the teeth. 



Fig. 716 



Fig. 7i: 




Class II. — When the lower jaw is distal to its normal relation with 
the upper jaw, and the lower first molars lock distally to normal, it must 
necessarily follow that every succeeding permanent tooth to erupt must 
also occlude abnormally, all the lower teeth being forced into positions 
of distal occlusion, causing retrusion and more or less underdevelop- 
ment, of the entire lower jaw. 1 This condition of distal occlusion is the 
determining characteristic of Class II. 

Of this class there are two divisions, each having a subdivision: 
Division 1 is characterized by distal occlusion of both lateral halves 
of the lower dental arch, a narrowed upper arch, protruding upper 



1 In this classification the writer has selected typical cases representing the first 
permanent molars in distal or mesial occlusion (in Classes II or III) the full width 
of the cusp, but it should be remembered that the complete distal or mesial locking 
of the molars is unnecessary to the correct placing of cases in their proper classes. 
but the mal-locking of the inclined planes of the cusps must be such as ultimately 
will lead to their full mesial or distal locking. See also pages 687 and 6SS. 



704 



ORTHODONTIA 



incisors, short and practically functionless upper lip, lengthened lower 
incisors, and thickened lower lip which rests cushion-like between 



Fig. 718 




the upper and lower incisors, increasing the protrusion of the former 
and the retrusion of the latter. A like condition is sometimes found in 









Fig. 


719 




• -:■:•■ 

■'v ,V ' ■£ 


jSrJ 


468 


46B 1 




■ft 




468 


468 ij^j 




;. ■'>' . .'- J; , > ,. 






•'- E^^^^ 






^v^^ 






ft^pY*/""^ ' 




IDE •- '"'I^|l Ik. 

[rigk 








m 

■ ^;468 


LEFT I 





younger patients who have as yet erupted only their deciduous teeth. It 
seems probable that cases of malocclusion belonging to this division 



CLASSIFICATION OF MALOCCLUSION 



705 



of this class are caused by some form of nasal obstruction necessitating 
mouth-breathing, which is usually an accompaniment — probably always 
in the early stages. 

There is great similarity in the malocclusion in cases belonging to 
this division, and the disturbance in the facial lines is also characteristic 
and pronounced. The malocclusion typical of this division of this class 
is shown in Fig. 718. 

Fig. 720 




Subdivision, Division 1, has the same characteristics, differing only 
in that the distal occlusion is unilateral, as shown in Fig. 719. This 
condition may also be found in the deciduous denture. 

Division 2 is characterized also by distal occlusion of both lateral 
halves of the dental arches, but by retrusion instead of protrusion of the 
upper incisors. In this division there are no complications from patho- 
logical conditions of the nasal passages, hence the mouth is kept closed 
the normal amount of time, and the lips perform their normal functions, 
which causes the repression of the upper incisors until they come in 
45 



706 



ORTHODONTIA 



contact with the lower incisors, causing bunching and overlapping 
of the upper incisors and canines, as shown in Fig. 720. 

Subdivision, Division 2, has the same characteristics as Division 2, 
differing chiefly in that the molar occlusion is unilaterally distal, as 
shown in Fig. 721. 

The marring effect on the facial lines of the malocclusion of Division 2 
and its subdivision is both marked and characteristic, but very different 
from that of Division 1 and its subdivision. 

Class III is characterized by the locking mesially to their normal 
relations of the inclined planes of the lower first molars in both lateral 
halves of the dental arches. This is but slight in the beginning, but as 



Fig. 721 




these cases are always progressive, the mesial occlusion may progress 
to include the full width of one or even two cusps, as in the extreme 
case shown in Fig. 722. In cases belonging to this class, the arrange- 
ment of the teeth in their respective arches varies greatly from quite 
even and regular alignment to considerable crowding, especially in 
the upper arch. There is usually a decided lingual inclination of the 
lower incisors and canines, which becomes more and more pronounced 
as the case progresses, and which is due to the pressure of the lower 
lip in the effort to close the mouth. 

In addition to the inharmony in the relations of the jaws, there is 
usually inharmony also in the sizes of the two dental arches, especially 
in fully developed cases, due to the asymmetrical development of the 



CLASSIFICA TION OF MALQCCL USION 



707 



Fig. 722 




Fig. 723 




708 ORTHODONTIA 

maxillary bones, the angle of the lower jaw being more obtuse than 
normal, but it may also be the result of overdevelopment in the body 
of the jaw. Other characteristics met with in this class are considered 
in the section on Treatment, page 864. 

In all cases belonging to this class the marring of the facial lines is 
most noticeable, and in direct proportion to the extent of malocclusion. 

Subdivision, Class III. — This subdivision differs from the division 
only in degree, one of the lateral halves of the arch only being in mesial 
occlusion, the other being normal, as shown in Fig. 723, the arches 
crossing in the region of the incisors. 

That all cases of malocclusion met with will be found to be embraced 
in the above classification is more than probable. There still remains, 
however, one possible class — viz., where one of the lateral halves of the 
lower arch is in mesial occlusion while the other is in distal occlusion; 
but cases having these characteristics are so very rare that no further 
reference to them is necessary, the writer having never seen but two 
or three cases. 

In diagnosticating cases according to the above classification, it will be 
seen that the occlusion of each of the lateral halves of the arches is 
important, and must be considered separately and with equal and care- 
ful attention, always beginning with the first permanent molars. In 
cases of malocclusion of very young children who have only their decidu- 
ous dentures, diagnosis should begin with the second deciduous molars. 

In developing cases of the second and third classes when the lower 
jaw may be in a state of transition and has not attained to distal or 
mesial occlusion the full width of a cusp on one or both sides, the beginner 
may be a little puzzled as to the proper classification; but upon careful 
inspection and close study a majority of the inclined planes will be found 
to favor one particular class, the co-relation of the first molars being, 
of course, the most important factor. 

The loss of a tooth or teeth by extraction is followed by such marked 
changes in the positions of the remaining teeth that diagnosis is some- 
times greatly complicated. Therefore, great care and judgment should 
be exercised, making allowance for the tipping of teeth and other changes 
which have taken place as a result of extraction, in order to determine 
their original positions. This point being decided, the correct diag- 
nosis according to the above classification becomes easy. 

A brief recapitulation of the classification is here given for convenience 
of study and for ready reference : 

Class I. — Arches in normal mesio-distal relations, with malocclusion 
of anterior teeth. 

Class II. — Lower arch distal to normal in its relation to upper arch. 
Division 1. — Bilaterally distal, protruding upper incisors. Usually 
mouth-breathers. 
Subdivision. — Unilaterally distal, protruding upper incisors. 
Usually mouth-breathers. 



FACIAL ART 709 

Division 2. — Bilaterally distal, retruding upper incisors. Normal 
breathers. 
Subdivision. — Unilaterally distal, retruding upper incisors. Nor- 
mal breathers. 
Class III. — Lower arch mesial to normal in its relation to upper 
arch. 
Division. — Bilaterally mesial. 

Subdivision. — Unilaterally mesial. 
Out of several thousand cases of malocclusion examined, the pro- 
portion per thousand belonging to each class was as follows: 

Class I 692 

Class II. 

Division 1 90 

Subdivision 34 

Division 2 42 

Subdivision 100 

Class III. 

Division 34 

Subdivision 8 

1000 



FACIAL ART 

Art, as related to the human face, must ever have an important 
bearing on the study of orthodontia, for the mouth is a most potent 
factor in making or marring the beauty and character of the face, and 
the positions of the teeth are to a very large extent responsible for the 
proper form and beauty— or the lack of it — of the mouth. No one 
can be beautiful unless the mouth is in harmony with all the other 
features, and no one afflicted with malocclusion can have a mouth that 
is thus in harmony. 

The duties of the orthodontist force upon him great responsibilities, 
and there is no subject in which the student of orthodontia should be 
more keenly interested nor better informed than in art generally, and 
especially as it relates to the human face; for each of his efforts, whether 
he realizes it or not, makes for beauty or ugliness, for harmony or inhar- 
mony, for perfection or deformity. 

But in order that our efforts may be intelligently directed toward 
the ideal, there must be some grand principle as a basis from which to 
reason, or we must be but gropers in the dark, experimenters, producing 
results which may cause embarrassment or even bitter regret. 

Though human faces are all greatly alike, yet all differ. Lines and 
rules for their measurement have ever been sought by artists, and many 
have been the plans for determining some basic line or principle from 
which to detect variations from the normal, but no line, no measurement, 
admits of anything nearly like universal application. 



710 ORTHODONTIA 

The beautiful face of the Apollo Belvedere has very largely been 
used as a guide toward the ideal and from which to judge variations, 
but this has been found to be impracticable and misleading; and this is 
easily understood when we remember that the Apollo face represents 
the type of the ideal Grecian beauty, while now the Greek type is 
rarely seen, and in its place we have, especially in America, many 
types and the greatest number of variations of each type, each face being 
a law unto itself, and presenting demands as to measurements and 
proportions wholly peculiar to itself. 

According to one of our foremost teachers of art, Mr. E. H. Wuerpel, 
there is a principle for our use which is equally applicable to all faces — 
viz., the principle of balance, of symmetry. We must be able to detect 
whether the features — that is, the forehead, the nose, the chin, the lips — 
of each individual face balance, harmonize, or whether they are out of 
balance, out of harmony, and especially whether the mouth is in harmo- 
nious relations with the other features, and, if it is not, what is necessary 
to place it in balance. 

The faculty of determining the proper balance of the features is a 
difficult one to attain. The authority above referred to says that only 
one in two or three hundred art students ever succeed in mastering it, 
and these only after much observation and practice in sketching and 
modelling faces. 

Unpromising as this seems, it is doubtless correct, yet we have a rule 
for determining the best balance of the features, or at least the best 
balance of the mouth with the rest of the features, that artists probably 
know nothing of, and one that for the orthodontist is more unvarying and 
more reliable than even the judgment of the favored few — a rule so 
invariable and with so few exceptions that we may consider it a law, 
and if it be not applicable in all cases, the exceptions will be so very rare 
that they are hardly worth considering. It is, furthermore, a rule so 
plain and so simple that all can understand and apply it. It is that 
the best balance, the best harmony, the best proportions of the mouth, 
in its relations to the other features, require that there shall be the full 
complement of teeth, and that each tooth shall be made to occupy its 
normal position in the architectural line of occlusion according to each 
individual type — normal occlusion. 

Fig. 724 shows the face of Apollo. The face is a study of symmetry 
and harmony of proportion, and such lines are wholly incompatible 
with teeth in malocclusion or with less than the full complement of 
teeth. 

Fig. 725 shows another face, which is also one of much beauty and 
fine proportions. It is also somewhat of a Greek type, and the lower 
half of the face shows lines which could only have been moulded over 
teeth normal in number, type, size, and position, and accompanied by 
normal conditions of development and nasal function. 



FACIAL ART 

Fig. 724 



711 




Fig. 725 



Fig. 726 





Fig. 726 1 shows a face that is a blending of the Greek and Roman 
types, and it also is in fine balance, although very different from that of 



William Whipple. 



712 



ORTHODONTIA 



Apollo. The features are large and prominent and the head is large, 
but there is a harmony of size, relation, and proportion that forms a 
most pleasing whole. The face, while in fine balance, is perhaps not 



Fig. 727 



Fig. 728 




Fig. 729 




beautiful from a physical standpoint, but it is more. It is beautiful from 
an intellectual standpoint, possessing strength, nobility, majesty — that, 
in the writer's opinion, is lamentably lacking in the Apollo face. 



FACIAL ART 



713 



Figs. 727 and 728, and Fig. 729 show the faces of two normally devel- 
oping children, although it will be observed that they are of strikingly 
different types. The proportions of the faces, the balance of the features, 







Fig. 730 


•" ^^^^^v ""* 




^g a* y-s 


'^^ttjf^Qt* ''^#i> ^ti0&0^ m l90£*^^ 






I 



and the harmonious lines of the mouths tell as truthfully that they are 
being moulded over dental arches developing normally, with teeth in 
normal occlusion, as the models of the teeth themselves, shown in Figs. 
730 and 731. 




In these cases nature has been able to work unhampered by detri- 
mental pathological conditions, which is apparent in the results. 



714 



ORTHODONTIA 



( )f course, it must be understood that changes in the contour of these 
young faces must take place with greater development. The noses and 
chins will develop and become more prominent, and after the eruption 
of the permanent canines there will be more of an acute angle between 
the nose and the upper lip, especially in the face shown in Fig. 729. 
But the point we would emphasize is the normal development and con- 
sequent normal balance and symmetry of these faces, and if we will 
notice any child that is developing normally, or any person who has 
reached maturity with the teeth in normal occlusion, we will find an equal 
harmony of balance of the mouth with the other features. Dr. R. Anema 
has well said that "probably the greatest reason why there is such uni- 
formity of harmony in the facial lines of young children is that their 
teeth (the deciduous teeth) are so free from malocclusion/ ' 



Fig. 732 




The writer would not be understood as implying that every face with 
lines and features in harmony of balance must necessarily be beautiful, 
nor even that placing maloccluded teeth in normal occlusion will always 
put the whole face in harmony of balance. There may be defects in the 
face, as lack of development of the nose or chin, or unequal development 
of the malar bones or of any of the bones of the face, or defects in the 
eyes or ears, or in the shape of the head, which, of course, could not be 
remedied by the correction of malocclusion alone, but the best harmony of 
such faces, or of any face, is only possible when the teeth are in normal 
occlusion. Malocclusion, or the loss of teeth by extraction or non- 
eruption, or a combination of these two causes, is responsible for far 
more faces out of balance and out of harmony than any other cause 
or combination of causes, and this inharmony and lack of balance of 
the mouth exists just in proportion to the degree of malocclusion. 

For a true understanding of what is meant by harmony of proportion 
and balance of faces, a careful study must be made of faces that are out 
of balance as well as of those that are in balance. 

The effect on the facial lines of the varying forms of malocclusion 
found in the three different classes varies not only with the degree of 
malocclusion, but also with the individual type of face, yet, notwith- 



FACIAL ART 715 

standing this, the type of facial deformity produced by each separate 
class of malocclusion is so constant that, after some practice, the close 
observer may classify with much accuracy the malocclusion of the 
people he observes without an actual examination of their teeth. This is 
also true in the case of extraction, or the loss or lack of teeth from any 
cause. 



Fig 




In Class I, the chin and nose will usually be found in relatively nor- 
mal balance with the forehead and general contour of the face, and 
the lines of abnormality confined more or less to the mouth itself. 

Fig. 732 shows such a case in the profile of a boy, aged fourteen years, 
and the lack of balance in the flat and sunken lines of the mouth 
clearly indicates diminished sizes of the dental arches. This lack' of 
normal contour of the mouth will be more impressive when it is remem- 
bered that at this age a boy's mouth should be relatively more prominent 
than that of a man, for the reason that his face has not yet reached its 
full growth, while the teeth are full-sized at eruption. 

Figs. 716 and 717 show the reason for this lack of normal contour, 
namely, lack in the development of the alveolar process and pronounced 
crowding of the teeth. 



716 



ORTHODONTIA 



The correctness of our rule is verified in the corrected occlusion, 
shown in Fig. 884, and in the restored facial lines in Fig. 733. 

Fig. 734 shows the profile of a young girl whose malocclusion belongs 
to Division 1, Class II, and the lines of inharmony shown in this face 
are characteristic of all cases of this division of this class of malocclusion, 
and also of the subdivision. 

In cases belonging to Class I, as we have seen, the mouth is the 
only feature greatly out of harmony; but in these cases the nose, the 
mouth, and the chin must be greatly out of balance, both with each 
other and with the general contour of the face, due to the type of 
malocclusion of this class, as illustrated in Fig. 718. 



Fig. 734 



Fig. 735 




To attempt to restore balance and harmony of proportion to this 
face by placing all the teeth in normal occlusion is perhaps to seem to 
put our rule to a severe test, but its correctness is shown in the result 
on the facial lines in Fig. 735, and while the face may still not be beau- 
tiful, we believe that by no other means could it have been placed in so 
nearly normal balance or harmony. 

It will be observed that this type of face differs greatly from the 
straight-line Apollo face; yet in cases of malocclusion both types of 
face are equally susceptible of being restored to the correct balance 
normal to each, and both by the same method — namely, the establish- 
ment of normal occlusion. 

Since in this case there have been established normal relations of the 
muscles and of the inclined planes of the teeth, and normal nasal 
respiration has also been established, the further development of this face 



FACIAL ART 



717 



will be toward the normal — toward harmony — instead of in the opposite 
direction, as had been the case since the day the nasal trouble first 
caused mouth-breathing, or since the first abnormal locking of the 
inclined planes of the first permanent molars. 

The disturbance of balance of the facial lines in the subdivision of 
this division differs, usually, only in degree. 

Fig. 736 shows the profile of a young man's face which is fairly 
typical of the lack of balance of facial lines due to malocclusion of the 
second division of Class II. The malocclusion is shown in Fig. 928. 



Fig. 736 



Fig. 737 




The head is large and well shaped, and the forehead and nose 
strong and in good balance, but there is a weakness about the mouth 
and chin that is greatly out of keeping with the general contour of the 
head. 

We have but to study the malocclusion to readily detect the cause, 
namely, distal occlusion with normal nasal and lip functions which have 
pushed the upper incisors back to occlude with the lower incisors and 
caused a crowding and overlapping in the upper canine region. 

Again, the rule was applied and each tooth made to occupy its normal 
position in the line of occlusion, with the most gratifying result on 
the facial lines, shown in Fig. 737. Those weak lines of inharmony 
have been changed to others of strength and harmony of balance, in 
contrast to the lines that must have followed had extraction been 
resorted to as the plan of treatment. 

The restored occlusion is shown in Fig. 929. 

The disfiguring effect on the face caused by malocclusion of the 
subdivision of this division of Class II are similar to those just shown 
in the full division. 



718 



ORTHODONTIA 



Fig. 738 shows the profile of a girl, aged thirteen, whose facial lines 
were thrown out of balance by reason of malocclusion of Class III, 
as shown in Fig. 948. 

A very superficial study of the malocclusion is sufficient to show us 
the reason for the flat upper lip and unnatural prominence and heavi- 
ness of the chin and lower lip. 

The applying of our rule, or the establishing of normal occlusion, 
produced the result in facial lines shown in Fig. 739, and in occlusion 
shown in Fig. 949. 

The subdivision of Class III is characterized by the same type of 
facial disturbance as the division. 



Fi< 



738 



739 





Thus far we have considered the marring effect on the facial lines 
resulting from malocclusion when the normal number of teeth is 
present; but there is another phase of malocclusion, the effects of which 
are very pronounced in the disturbance of the facial balance, namely, 
the all too common loss of teeth from mutilation by extraction, or their 
occasional non-development, or non-eruption, and the disturbance in 
facial balance will be in exact proportion to the extent of the loss or 
lack of teeth. 

The loss of even a single tooth not only produces great inharmony 
of occlusion, but equal inharmony in the facial lines. Fig. 740 shows 
the profile of a young girl whose upper right lateral incisor failed to 
develop, as was revealed by the ;r-rays, and the resultant inharmony in 
the relations of the upper and lower lips, as well as the unpleasing 
angle between the upper lip and nose, is readily seen. It can be imagined 
how great would have been the improvement in the facial lines had 
that tooth developed normally and the upper arch been enlarged to 
accommodate it. 

Since this is true, what must we think of the frequently advocated 
practice of extracting one or both lateral incisors or even canines in the 
hope of improving the facial lines ? 



FACIAL ART 



719 



The profile on the left of Fig. 741 shows the effect on the facial lines 
of an effort to prevent malocclusion by the extraction of the perfectly 
sound four first permanent molars at the age of nine years, which 
is in keeping with a belief still practised by many of the old school. We 
need possess very little artistic perception to readily detect the great 
inharmony of the mouth with the other features. The lack of balance 
is so pronounced as possibly to create the impression that all the teeth 
have been lost, and that the patient is wearing badly proportioned 
artificial dentures. 



Fig. 740 




The profile on the right of Fig. 741 shows the facial lines restored 
to normal balance, or as nearly so as was possible at that age of the 
patient, established by the placing of the teeth that remained in their 
normal relations. Fig. 899 shows this, and the case ready for the inser- 
tion of artificial substitutes for the missing molars. 

Fig. 742 shows the profile of a face where extraction of both upper 
first premolars was resorted to by the writer several years ago in 
carrying out the old plan of treatment for the reduction of "labial 
protrusion of the upper incisors," or a case belonging to Division 
1 of Class II. The effect of this treatment, instead of improving the 
facial lines, especially the angle of the nose with the upper lip, was to 
cause their greater inharmony and has been the occasion of lasting 
regret. 

The writer wishes to indelibly impress on the mind of the student 
that since normal balance of the lines of the mouth with those of the 
other features is dependent on the normal occlusion of the teeth, they are 
necessarily thrown out of balance and out of harmony just in proportion 



720 



ORTHODONTIA 



Fig. 741 




Fig. 742 




ETIOLOGY OF MALOCCLUSION 721 

as the teeth are out of normal occlusion, and that since extraction always 
produces malocclusion just in proportion to the number of teeth ex- 
tracted, where malocclusion did not previously exist, and exaggerates 
and complicates it where already existing, its effect on the facial lines 
is inevitably as inharmonious, not to say deforming, as its practice is 
unpardonable. 

Extraction is further discussed in the section on Treatment. 



ETIOLOGY OF MALOCCLUSION 

As we have already noted, malocclusion is the result of failure on 
the part of nature to carry to completion the normal plan of building 
the human denture — the arrest or modification of the forces operative 
in the building. As these forces are numerous and necessarily compli- 
cated by their co-relations, it is not surprising that the perfectly normal 
human denture is rarely found. Indeed, the perfectly normal in dentures, 
as in human beings, or in the lower animals, or in plants, is rare. If the 
conditions for growth and development of the teeth and jaws, bones of 
the face, the throat, the nose, the muscles, etc., are normal, a normal 
denture will be the result; but a long time is necessary for the building 
of the denture, and many obstacles may intervene to prevent its normal 
unfoldings in growth. Indeed, any pronounced interference with the 
growth of any of the different factors may, and usually does, result in 
malocclusion of the teeth. As, for example, any pathological condition 
of the nasal passages, resulting in the necessity for mouth breathing, 
will not only prevent the normal growth of the nose, but will modify 
the vault of the arch, and so pervert the forces of the lips as to cause 
serious disturbance in the dental arches and the relations of the teeth, 
as is shown in cases belonging to Division 1, Class II. And not only 
this, but serious disturbances in the growth, health, and development of 
the child also often result from mouth breathing. Again, it is the 
writer's belief that abnormal enlargement of the faucial tonsils is the 
principal cause in the production of malocclusion belonging to Class III, 
at least in the primary stages, the enlarged tonsils seeming to provoke 
a desire on the part of the child to habitually shove the lower jaw forward 
until mal-locking of the cusps of the molars results. Thus, perversion of 
occlusal and muscular forces is brought about and the most progressive 
of all forms of malocclusion established. 

Premature Loss of Deciduous Teeth. — The deciduous teeth not only 
perform the important function of masticating the food required by the 
child up to the period of their normal loss and their replacement by the 
succeeding permanent teeth, but they also assist in a mechanical way in 
the development of the alveolar process, and probably in the develop- 
ment of the jaws as well. 
46 



722 ORTHODONTIA 

The permanent teeth being larger and more numerous than the 
deciduous, the greater space required for them is provided principally by 
the lengthening of the lateral halves of the dental arches. This is influ- 
enced largely by the development and eruption of the permanent molars 
posterior to the deciduous molars. If the mesio-distal diameters of the 
deciduous teeth be not impaired by caries and the teeth remain the 
normal period, the first permanent molar in taking its position in 
the arch must force its way between the second deciduous molar and 
the ramus of the jaw, if below, or the maxillary tuberosity if above. 

Coincident with the growth of the bones of the head and face the 
maxillary bones are developed downward and forward, the mandible 
lengthened and deepened, and the deciduous teeth carried forward. 
If, however, one of the deciduous teeth be prematurely lost, as, for 
example, the upper second molar, the erupting permanent molar will 
be unable to exert its normal force in crowding the deciduous teeth 
forward, but instead, meeting with no resistance, it will move forward 
prematurely and more rapidly than normal, into the space of the missing 
tooth. If, meanwhile, no teeth have been lost in the same side of the 
opposing arch, the wedging process will have pushed forward the 
lower deciduous teeth and the more normal development in the lower 
arch will have occurred. There will thus be an inequality between the 
jaws on the affected side with the establishment of malocclusion. And 
this is not the only evil, for the space occupied by the lost tooth having 
been closed or greatly diminished, the eruption of the succeeding per- 
manent tooth (the second premolar) will be prevented entirely, or it 
will be forced into buccal, or, possibly, lingual occlusion, as in Figs. 743 
and 744. The shortened lateral half will not develop, and the upper arch 
will consequently be smaller than normal, which must result in mal- 
occlusion of the teeth. 

A point of much importance in connection with this phase of the 
subject which may as well be discussed here is that, although the 
first permanent molar is temporarily displaced by its moving prema- 
turely forward, the writer believes it is always found in its normal 
mesio-distal position, even in these cases, ultimately, or at the time 
of the completion of the denture. Indeed, even in two cases in each 
of which three upper premolars had failed to develop, the first perma- 
nent upper molars were not found farther mesially than normal at the 
maturity of the patient. And the reason is plain. There was nothing 
to force them forward after the second and third molars had taken 
their places in the arch and ceased their wedging influence, all the 
lack of development of the arch, which was great, being in its anterior 
portion. 

This premature movement of the molar to its ultimately normal 
position is easily understood by a study of Figs. 743 and 744, which show 
two instances in which premature loss of deciduous second molars resulted 



ETIOLOGY OF MALOCCLUSIOX 



723 



in malocclusion, one shown during the growth of the denture and 
the other at maturity. 

Another point of interest in connection with this subject is that this 
displacement mesially may, and often does, result in the mal-locking 
of the lower first molars with the upper, and in this way becomes the 
prime cause of the establishment of the subdivision, or, if on both sides, 
the full second division of Class II. 



Fig. 743 




While probably the greatest harm results from the premature loss 
of the second deciduous molar or canine in either arch, the principle 
applies to the loss of any of the deciduous teeth, the difference being 
only in degree. 

Fig. 744 




The mechanical influence of the deciduous teeth in the development 
of the dental arches is so important that they should not only by all 
means be retained their full normal period, but, if they become affected 
by caries, their full mesio-distal diameters should be restored by suitable 
fillings after sufficient separation. Likewise, if a deciduous tooth be 



724 ORTHODONTIA 

lost through the premature absorption of its root, the full space occupied 
by it should be maintained by some suitable retaining device. 

Prolonged Retention of Deciduous Teeth. — One or more of the deciduous 
teeth are occasionally retained beyond the normal period. In this 
event the succeeding tooth will either be prevented from erupting or 
will be deflected to a malposition. 

Loss of Permanent Teeth. — What has already been stated in regard 
to the mechanical influence of the deciduous teeth in assisting the nor- 
mal development of the dental arches and promotion of harmony of the 
facial lines is equally applicable to the permanent teeth up to the period 
of their full eruption, or until the last of the molars has taken its 
position. This is a point of such importance that it should be carefully 
considered by all students of occlusion. If one or more of the permanent 
teeth anterior to erupting molars be extracted, the wedging process, 
so necessary in developing the arch, serves only to close the space thus 
made, and there will be no carrying forward of the teeth and process. 
The evil effects already enumerated as arising from unequal develop- 
ment of the two arches will follow. It should also be borne in mind 
that the interdependence of the teeth is so great at all times that the 
loss of one or more at any period in their history must have a marked 
influence on the remaining teeth. Especially is this true of the loss of 
the lower first permanent molars. (See page 830.) 

Tardy Eruption of Permanent Teeth. — It occasionally happens that a 
tooth, with or without apparent cause, fails to erupt, and remains 
embedded in the alveolar process for months, or even years. Usually 
the space is partially or wholly closed by the adjoining teeth. The im- 
paction of the canine is the most common of any of the teeth, owing to 
the fact that it erupts after both its mesial and distal associates, and 
must in all cases meet more or less resistance from them. If, later, 
efforts toward eruption occur, the tooth must necessarily be deflected, or 
force other teeth into malposition. 

Supernumerary Teeth. — Supernumerary teeth, as their name implies, 
are anomalies, or extra teeth above the normal number of thirty-two. In 
outline they rarely resemble any of the typical tooth forms, being most 
commonly peg-shaped or conical. Although they may erupt in any 
part of the dental arches, or even nearly cover the entire vault of the upper 
arch, as shown in a model in the writer's collection, and also in two or 
three other well-known cases, their favorite location is between the 
central incisors, in the region of the laterals, or in the bucco-embrasial 
spaces between the molars. The reason for their appearance is not 
clearly established. 

Habits. — The habit of sucking the thumb, lip, or tongue, or that 
modern and highly pernicious instrument known as a "pacifier," so 
frequently formed by young children, will not only cause malocclusion 
of the deciduous teeth, but may and often does so pervert the functions 



ETIOLOGY OF MALOCCLUSION 725 

of the lips or tongue as to ultimately lead to marked malocclusion of the 
permanent teeth. 

The pernicious habit of biting the lower lip, or pressing the occlusal 
edges of the upper teeth against its outer surface, has a tendency to move 
the upper centrals forward, thus lessening their natural resistance to the 
narrowing of the lateral halves of the arch. 

This habit is very common, is often extremely difficult to overcome, 
and probably accounts for many ultimate failures in orthodontic treat- 
ment. It is always a marked accompaniment of cases belonging to 
Division 1 of Class II and its subdivision, and unless it be overcome 
and the normal functions of the lips regained, the incisors cannot be 
kept in their normal positions. 

Another habit, although more rare, that of resting the tongue between 
the upper and lower incisors, produces the effect shown in Fig. 745. 

Fig. 745 




The pressure upon the incisal edges prevents full eruption and holds 
the teeth in infra-occlusion, while the molars, being held apart much 
of the time, lengthen into positions of supra-occlusion from lack of 
resistance. 

Disuse. — The structure and history of the jaws and teeth show that 
they were intended for much use. There can be little doubt that the 
modern methods of food preparation tend to such disuse of the jaws 
and teeth as to have a marked general effect in causing malocclusion. 

Abnormal Frenum Labiorum. — A somewhat common form of malocclu- 
sion is distinguished by a space between the upper central incisors, and 
occasionally, although very rarely, between the lower centrals. This 
space varies in width from one to four and even five millimeters, always 



726 ORTHODONTIA 

presenting an unpleasing appearance and interfering with speech in 
proportion to its width. The cause of the deformity is abnormal develop- 
ment and attachment of the frenum labiorum, which, instead of being 
normal in size and ending in its attachment to the gum about five milli- 
meters above the gingiva, not only reaches the gingiva, but passes 
directly between the teeth and is attached to the likewise overdevel- 
oped mesio-lingual tuft. This strong fibrous ligament keeps the teeth 
separated by its mechanical action. 

There are other causes of malocclusion, many of which are not 
clearly understood, and their discussion here would be unfruitful. One 
which has claimed much prominence in the past is heredity. It is 
now, however, believed that heredity plays an unimportant part in 
the production of malocclusion, and that most of the causes are 
mechanical and operative subsequent to birth. 



ALVEOLAR PROCESS AND PERIDENTAL MEMBRANE 

The importance of a thorough knowledge of the alveolar process 
and peridental membrane is perhaps greater in orthodontia than in any 
other branch of dentistry, for to the orthodontist these tissues are second- 
ary only in importance to the teeth themselves; and it is largely owing 
to our intelligent comprehension and handling of these tissues that 
we are enabled to successfully correct malpositions of the teeth. It 
is unnecessary to here enter into an extended discussion of these struc- 
tures. 

No thoughtful person can study the arrangement of the fibers of the 
peridental membrane without being impressed with their wonderful 
perfection of adaptation for resisting the various tooth movements 
incident to occlusion and mastication, and a knowledge of this arrange- 
ment is of peculiar interest to the orthodontist, enabling him to better 
comprehend not only the amount of force required and difficulties to be 
overcome in moving teeth, but the necessary anchorage to be gained 
from teeth in performing the operation, as well as a far better insight 
into problems of retention. 

Tissue Changes Incident to Tooth Movement. — When the proper amount 
of force is exerted upon the teeth to be moved, "the bending of the pro- 
cess, and the absorption of bone, principally of the cancellous structure 
between the external and internal plates," 1 occurs. 

In youth, or before the bone has become dense, it permits of much 
bending, so that incisors may be moved out of inlock in a few hours, 
or the lateral halves of the arch may be widened in a very few days. 
This is easily explained when we remember the cancellous structure of 

1 Dr. F. B. Noyes. 



ALVEOLAR PROCESS AND PERIDENTAL MEMBRANE 727 

the bone, the inelasticity of the fibers of the peridental membrane, and 
their very strong attachment to it. 

While more or less springing of the bone is probably always an accom- 
paniment of tooth movement, yet in proportion as the bone becomes 
dense with age, so the modification of the process attendant upon 
tooth movement changes from springing to the slower action of absorp- 
tion and the still more slow deposition of bone. 

Coincident with the changes in the bone there are also pronounced 
changes taking place in the peridental membrane. As force is exerted 
on the moving tooth the membrane is compressed in front of it, between 
it and the wall of the socket, while a greater tension of the fibers of 
the membrane takes place on the opposite side. As a result of this 
tension and compression the nerves of the membrane are impinged 
upon, causing a greater or less sense of pain, which, as a result of the 
slight movement of the tooth and temporary paralysis of the nerves 
from pressure, subsides more or less quickly according to the amount 
of inflammation present. 

As a result of this pressure the absorbent cells, or osteoclasts, are 
stimulated to increase in number and activity. They immediately 
engage in the absorption of the portion of bone most involved in the 
movement, as well as of the bone attachments of the fibers on greatest 
tension. 

While these changes are taking place the osteoblasts have become 
active, and have begun filling up the depression and reattaching the 
fibers by the redeposition of bone. But as this is a much slower process 
than that of absorption, the tooth is found to be more or less loose in 
its socket at the completion of its movement, as well as long after, 
necessitating its being supported by means of the retaining devices 
until the deposition of bone shall be complete and the socket modified 
for its support in its new position. 

If a tooth be elevated in its socket, the principal change involves 
the peridental membrane. The fibers at the end directly resisting this 
movement are severed, and the oblique or suspensory fibers are stretched 
and recurved upon themselves. The result of the partial withdrawal of 
the conical root is increased space, not only at the end, but also on the 
sides of the root, so that there is considerable freedom of movement of 
the tooth, necessitating the deposition of bone over the entire surface 
of its socket, as well as increase of height of margin and a reorganiza- 
tion of the entire system of fibers. This explains the necessity for 
such protracted suspensory retention, and the comparative ease with 
which the movement of elevation may be performed. 

In the movement of depression — the most difficult tooth movement 
— the bone must be absorbed by the osteoclasts over the entire surface 
of the alveolus to allow for the advance of the root of conical form. 
The fibers of lateral support are stretched, while the suspensory fibers 



728 ORTHODONTIA 

are also stretched, and severed at their points of attachment to the bone, 
thereby necessitating more disturbance of tissues and requiring more 
force and time than any other of the seven movements. 

In the rotation of a tooth, as probably most of the fibers indirectly 
tend to prevent the tooth from turning in its socket, and, in addition, 
there are an unusual number at the four angles so arranged as to directly 
resist such action, much absorption of the fibers, as well as much absorp- 
tion and bending of the bone are necessary, which easily accounts for 
the greater amount of time and force required to perform this movement. 

In all cases of tooth movement a large number of the fibers of the 
membrane, as well as the bone, remain on tension long after the move- 
ment is complete, the force they exert tending to draw the tooth back 
to its original position, thus necessitating considerable support from the 
retaining devices until these tissues, as well as the muscles, have become 
thoroughly reestablished in harmony with the tooth in its new position. 

In accomplishing the movement of teeth lingually, labially (or buc- 
cally), mesially or distally, the principal change is in the position of the 
crown of the tooth, it being tipped into its correct position. The usual 
supposition is that the tooth in the alveolar process acts as a lever, 
the crown, or long end of the lever, moving in one direction, and the 
apex of the root in the opposite direction. To make clear these sup- 
posed changes, and especially the extent of the movement of the apex, 
writers have frequently used the illustration of a post driven about two- 
thirds its length into the earth. If force be exerted at right angles to 
a side of the post near its top, the post will act as a lever in the dis- 
placement of the soil, the two ends of the lever moving in opposite 
directions, and the pivotal point being somewhere near the beginning 
of the last third of the embedded portion. 

The illustration is a poor one and very misleading, as the mechanical 
conditions are very different. Doubtless this would be the result if 
the tooth, like the post, had but one resistant substance and that equally 
distributed in all directions about its root; but, as is shown by a study 
of the alveolar process, the bone varies greatly in thickness over dif- 
ferent portions of the root and in different teeth, so the amount of 
displacement of the apex of the root of a tooth depends, frequently, upon 
the location and the movement of the tooth, and whether one tooth or 
a number in the same region are being moved in the same direction. 
In reality there may be little or no displacement of the apex, or there 
may be considerable. 

In the first place, the alveolar process is not a level plane, like that 
in which the post is implanted, but a projection or high ridge, of elastic 
structure, and admits of some bending laterally, its susceptibility to 
this action increasing proportionately as we approach the top. The 
pronounced bending of the process is a matter of common observation 
in efforts at extraction. 



ALVEOLAR PROCESS AND PERIDENTAL MEMBRANE 729 

Again, the mechanical difference in the attachment of the post to 
the soil and the tooth to the alveolar process is such as to still further 
add greatly to the difference in the results of their respective movements. 
As the apex of the root is implanted deeply in the bone, which is greatly 
thickened in its lingual direction and reinforced by the strong cortical 
layer of the alveolar process, its movement lingually could not well 
take place as a result of springing. This movement is further strongly 
resisted by the innumerable inelastic fibers that encapsule the apex, 
radiating in all directions for its firmest possible attachment to the bone, 
their ends being enclosed in its structure. 

So in the labial movement of the crown, the lingual movement of 
the apex of the root is not only resisted by the bone in front, but also 
behind and on each side, by reason of its attachment, while with the end 
of the post little, if any, resistance is offered by the soil behind or on 
either side, but only by that in front. 

Another difference. The force for the movement of the post is 
applied remote from the fulcrum, while the force exerted on the tooth 
by the ligature is applied close to the fulcrum, or at a point best calcu- 
lated to facilitate the bending of the alveolar process in the labial 
direction. 

Again, unlike the post, several teeth may be associated in the move- 
ment, which adds still further to the probabilities of the labial, as well 
as adding correspondingly to the improbabilities of the lingual move- 
ment of their apices. 

In the movement buccally of the upper molars there is bending or 
absorption of the outer plate, the palatal roots are elevated in their 
sockets to make easier the tipping of the crown, with probably no move- 
ment at the apices of the buccal roots, unless it be that they are forced 
deeper into their sockets. In the lingual movement of the same teeth 
there is more or less bending of the process, the forcing deeper into its 
socket of the palatal root, with perhaps some elevation in their sockets 
of the buccal roots. 

In the same movements of the lower molars there is greater displace- 
ment of the apices of the roots in the opposite direction from which the 
crowns are moved, owing to the great thickness of the buccal plate of the 
alveolar process. 

In the movement of teeth mesially or distallv the bending of the bone 
must be less, the movement of the teeth more nearly resembling the 
movement of the post, the apex moving slightly in the opposite direction 
from the crown, as in Fig. 801. 

The Pulp. — While the pulp of the tooth is a tissue more or less involved 
in tooth movement, when the operation is properly performed this 
tissue is practically undisturbed and should suffer no real injury. On 
the other hand, its normal function may be so interfered with as to 
cause it to suffer marked disturbance and even complete devitalization, 



730 ORTHODONTIA 

especially if the movement be conducted too rapidly, or the force be too 
abruptly applied. With modern regulating appliances, however, the 
most perfect control of the force for the movement of teeth is now easily 
possible, so that other than very slight inflammation is inexcusable. 

It is often desirable to perform tooth movement soon after the 
eruption of the teeth, or before the root is fully formed, the end of 
the root then having a broad, funnel-shaped opening. If the movement 
be intelligently performed, the pulp at this age should suffer no greater 
disturbance than when the root is fully calcified. 

Physiological Changes Subsequent to Tooth Movement. — Important 
physiological changes in the tissues involved also occur subsequent 
to tooth movement. To better understand these changes we must 
keep in mind the conditions previously existing. The development of 
malocclusion is gradual, and, in proportion as the positions of the teeth 
deviate from the normal, a corresponding deviation is necessitated 
in the development of the alveolar process, and, to a greater or less 
degree, in the bones of the jaws, vault of the arch, the nasal tract, and 
the muscles of the face. All being out of harmony, the tendency is usually 
to favor still greater inharmony, or departure from the normal, as growth 
and development progress. 

After the crowns of the teeth have been moved into correct positions 
in the line of occlusion and harmony of the occlusal planes has been 
established, the positions of the teeth and function of the occlusal planes 
have been so changed as to exert a different influence upon the bones 
and muscles. The tendency of the forces now is to stimulate nature 
to efforts toward the rearrangement of these tissues and their normal 
growth and development, in accordance with the demands of the teeth 
in their new positions and with her original design. Evidences are 
common throughout surgery of nature's wonderful inherent power to 
remedy her defects, and of her prompt response as soon as favorable 
conditions for self-assertion have been established. The natural changes 
following the correction of malocclusion are often pronounced and 
gratifying. 

The cognizance of the possibilities of these changes should in many 
instances modify our plan of treatment from what it would be were 
we ignorant of them. Very frequently where there has been change 
of position of a number of teeth, especially in both arches, some may 
occupy planes of greater elevation than others, or the cusps of some 
may not occupy exactly normal mesio-distal relations; but if we have 
succeeded in placing the teeth so that the inclined planes of their occlusal 
surfaces favor their normal positions, their proper heights and relations 
will gradually become established as a result of occlusion. In some 
cases the incisors may apparently be much too short, but after a few 
weeks or months, when the posterior teeth shall have become settled in 
their new positions, the length of overbite of incisors will be normal. 



ALVEOLAR PROCESS AND PERIDENTAL MEMBRANE 731 

Another noticeable and most important change following tooth move- 
ment is the growth of the alveolar process, as well as that of the co- 
related bones, muscles, and tissues which have been arrested in their 
growth as a result of malocclusion and the perversion of the function 
of the teeth. This is illustrated in the following case of historical interest, 

Fig. 746 




Figs. 746 and 747, where the pronounced arrest of these tissues is noted, 
especially that of the alveolar process in the region of the roots of the 
upper incisors and vault of the arch. 

After the arch had been enlarged and the crowns of the incisors 
carried forward, the positions of the teeth are shown in Fig. 748, which 



Fig. 747 




marks the beginning of the period of retention. But it will be noted 
that the incisors stand at a very pronounced angle of inclination, with 
the deep depression over the apices of the roots of the incisors more 
pronounced. 



732 



ORTHODONTIA 



After faithful mechanical retention for nearly three years, a gratifying 
discovery was made, which is noted in Figs. 749 and 750, namely, the 
complete normal development of the alveolar process and the shifting 
forward of the apices of the roots of the incisors until these teeth stood 



Fig. 748 



Fig. 749 




in their normal upright positions. The vault of the arch has been 
remodelled, the floor of the nose widened, and probably the maxillary 
and co-related bones and tissues have been greatly modified toward the 
normal in development. 

This was, indeed, a gratifying discovery to the writer, 1 for he realized 
that it was the fulfilment of a physiological law of growth following the 



Fig. 750 




establishment of normal occlusion and normal function of the teeth. 
He has since verified this in a large number of other cases, many of which 
were much more pronounced in the arrest in their development than 



Angle, Malocclusion of the Teeth, 7th edition. 



MODELS 733 

this case. It is now standard practice and there can no longer he any 
excuse for the extraction of teeth in these cases, founded on the time- 
honored supposition of the old-school practitioners that the jaws are too 
small for the teeth. 

Other cases verifying this law will be shown in the section on 
Treatment. 

It is well to remember that this subsequent development is very active 
and quick to respond in youth, or during the period of eruption of the 
incisors and for some years later, but that it diminishes in activity in 
proportion to the age of the patient — another strong evidence of the 
importance of early treatment of malocclusion. 

That the bone cells may be stimulated and more rapid and com- 
plete development effected in these cases by mechanical means is now 
proved. 

That the most favorable tissue changes possible may follow tooth 
movement it is, of course, of the utmost importance in all cases that all 
pathological conditions of the throat and nose receive the most careful 
attention from the skilful rhinologist. ' 



MODELS 

The first step in the study of all cases preparatory to treatment is 
the taking of accurate impressions of the teeth, from which accurate, 
articulating models of both arches are made. Such models not only 
assist in the classification and diagnosis of cases, but also aid in deter- 
mining the proper plan of treatment, and are also exceedingly valuable 
for reference during its continuation, for by comparing the models with 
the natural teeth at each visit of the patient we may not only keep 
positively informed as to the exact movements of the malposed teeth, 
but any unfavorable movement of the anchor teeth may also be imme- 
diately detected. 

Material for Impressions. — Models are only valuable in proportion 
as they are accurate, and the only models approximating accuracy are 
those made from plaster impressions. These models must show not 
only both arches and the relative positions of the teeth and cusps, as 
well as the vault of the arch, ruga?, and gums, but must also correctly 
show as much of the roots and their positions as are indicated by the 
gums and alveolar process up to the point where the attachment of the 
muscles renders obscure the further shape of the jaw. 

Models sufficiently perfect cannot be made from impressions taken 
in modelling compound or other of the plastics. 

The shape of the jaw, together with the shapes and inclinations of 
the teeth, make the removal of a plastic impression, without change of 
form, impossible. The degree to which arrest of development of the 



734 ORTHODONTIA 

alveolar process has taken place, especially in the region of the roots 
of the incisors, so important to accurately record in the model, can only 
be the merest supposition in a model made from a plastic impression. 

Fig. 751 




When the correct method of taking plaster impressions has been 
learned the operation occasions but little, if any, more trouble to the 
operator, or objection from patients, than if one of the plastics were 
used. 

Fig. 752 




The Trays. — The writer's trays, shown in Figs. 751 and 752, are 
best suited, being much higher than the ordinary trays. In taking an 
impression a sufficiently large tray should be selected, which should, 
if necessary, be bent to conform more nearly to any peculiarity in the 
shape of the jaw; this will not injure the tray. 

Taking the Impressions. — Good impression plaster is mixed in the 
usual way and carefully distributed, as shown in Fig. 753, the shape 



MODELS 735 

and height of the trays making but little impression material necessary. 
It will be observed that the greater amount is placed in the anterior 
part of the tray and made to extend over the outer edge of the rim, 
none being allowed in the vault of the tray. 

It is now placed squarely in position and the plaster allowed to rest 
evenly in contact with the occlusal edges of all the teeth, but not forced 
up into position. The lip is then raised, and the plaster extending outside 
of the rim of the tray is carried high up underneath it with the finger. 
This is to insure the expulsion of air, as well as a high impression. 
The tray is then forced up evenly until the points of the teeth touch 
the bottom of the tray, and steadily supported upon the end of the 
index finger only. To expel the air from the cheeks they are now gently 
manipulated, but not drawn down, as to do this would force down 
a portion of the plaster and prevent one of the important objects — 
viz., a very high impression. 

Fig. 753 




It should be allowed to remain in position until the plaster has become 
thoroughly set, which is very important, as the harder the plaster is 
allowed to become, the sharper will be the impression. 

The tray is now loosened and taken away, leaving the impression in 
the mouth. It is essential that the tray should loosen easily from the 
impression; hence the importance of its being kept clean, bright, and 
smooth. 

Two grooves are then scraped or cut in the hardened plaster on a 
line parallel with the canine teeth, but not cut quite through. Then 
with a quick pry with the point of a knife the anterior plate is loosened. 
The lateral pieces are then broken off with the thumb and finger, when 
the large piece covering the roof of the mouth alone will remain. This 
may be readily worked loose, and if the operation has been carefully 
performed the impression will consist of four pieces, although to have a 
much greater number would in no way injure it. 



736 



ORTHODONTIA 



After the pieces of the impression are dry they are united by means 
of wax, and should present the appearance illustrated in Fig. 754. 

This method of taking impressions preserves the fine points of the 
interdental spaces. We believe it to be the only practicable way of taking 
an accurate impression. 

In like manner the impression of the lower arch is taken, removed, 
and united, being careful to observe the essential points, namely, carry- 
ing the impression material, which has been built up and outside of the 
anterior part of the rim of the tray, well down beneath the lip with the 



Fig. 754 




finger, and after forcing the tray home the excess plaster on the sides is 
carried back and down to avoid folds in the cheek, while the tray is 
steadily held by the ends of two fingers of the left hand, one to rest on 
the top of each lateral half. 

Varnishing the Impression. — The impressions being united, they 
should be coated very evenly with shellac varnish. At the expiration 
of half an hour, or when the varnish has become hard, a second coat 
should be applied over the occlusal surfaces of the teeth and rough 
points only, not over the smooth surfaces, especially the labial gum 
surfaces. Dry again, and then apply over the entire impression a very 
thin, even coat of sandarac varnish. 1 



1 It is important that both of these varnishes shall be of the proper consistence, 
which is difficult to describe. If too thin, the hard, glossy surface will be wanting, 
and it will be difficult to separate the impression without injury to the model. If 
too thick, all fine tracings of the impression will be obliterated. 



MODELS 



737 



The Models. — After drying for half an hour the impression will be 
ready for filling, which may be best accomplished, in order to insure 
expulsion of air bubbles, by quickly and carefully painting the plaster 
into the tooth cavities with a small camel's-hair brush, then rapidly 
filling with a spatula, gently shaking for a while (never jarring), after 
which it should be turned bottom upward on a glass slab and allowed 
to thoroughly set. 

Numerous horizontal and vertical grooves are then made in the 
impression (Fig. 755) and it is also shaved thin over the occlusal sur- 
faces of the teeth, to expedite the separation of impression and model. 
Should any air cavities be found in the model, they may be remedied 
by the use of a delicate brush in the artistic application of plaster of a 
creamy consistence. A cusp or broken tooth may in like manner be 
repaired. 

Fig. 755 




The models may now be trimmed, and not only will there be a surface 
as smooth as polished marble, but each cusp, all the interdental spaces, 
and the rugse, as well as the inclinations of the roots, and even the 
minute " stipples" of the gum, and the developmental lines of the enamel, 
will be accurately and beautifully shown. Any coating of paint or 
varnish only detracts from the beauty of such models. 

The models should be trimmed according to lines of graceful propor- 
tions and artistic balance, which is made much easier by the use of the 
model plane and combination square, shown in Fig. 756. 

After they are trimmed, the models should be carefully compared 
with the natural teeth, and the occlusal relations indicated by two or 
more pencil markings, so that the proper points of contact may after- 
ward be readily found. These serve the purpose much better than any 
form of an articulator. 
47 



738 



ORTHODONTIA 



As soon as the teeth have been completely moved, another impression 
should be taken and models made. This is done after all appliances 
have been removed and the teeth thoroughly cleansed, and immediately 
previous to adjusting the retaining devices. These models are invaluable 
for comparison with the natural teeth during the period of retention, as 
well as for future reference. 1 

A collection of fine, accurate models is not only an incentive to keener 
interest and better work, but is a most valuable form of "library" in 
itself, in which much that is instructive and interesting is recorded 
that can never be reduced to writing. 

Models should never be mutilated by the fitting of bands and appli- 
ances. While they may serve as a basis for general measurements for 
the appliances, the fitting can only be properly done on the natural 
teeth. 



Fig. 756 




m.j. ,.,.,., | . | , •■'::::.:>"'5i« 

. i ■ I ' 1 : ■',,■' . ' . : ■. 1 : i ! ■ : i ■ ■ : ' ' ■ i ■ i ' 1 , i : ! . ! , i ; , ; ; , i : - ■ ' ^ ■ i , ; ; 1 1 1 ■ ; 1 . ; 1 ■ . ! ^ i , [ , , I i ^ 



Model plane. 

Photographs. — Quite as important as models are good photographs 
of the patients' faces, in which are represented full profile and front 
views in a simple, natural pose. These are far preferable and more 
reliable in judging the harmony and inharmony of the patient's face than 
is a plaster cast of the face. 

Rontgenographs. — Rontgenographs, now so easily and quickly made, 
are often of great value in settling all doubts as to whether teeth be missing 
or their exact locations and forms if merely embedded. While these 
points may be determined in the majority of cases by careful inspection 
of the contour of the alveolar process, and digital pressure, together 
with the use of the exploring needle, yet when any doubt exists the 
rontgenograph should be resorted to. Fig. 757 illustrates a case as 
revealed by the rontgenograph, where the canine is so deeply embedded 
in the alveolar process as to baffle the ordinary methods of diagnosis. 

1 For a more complete study of the writer's method of impression taking and 
model making the reader is strongly recommended to a most thorough treatise in 
booklet form on this subject, by Dr. Jos. Griinberg, of Berlin, for sale by the S. S, 
White Dental Mfg. Co. 






REGULATING APPLIANCES 739 

Fig. 758 shows the rare case of a missing permanent canine, and 
the absorption of the root of the deciduous canine. The first premolar 
is about to erupt. 

Fig.' 757 Fig. 758 





REGULATING APPLIANCES 

Two plans are now followed in the designing and constructing of 
regulating appliances, the first based upon the belief that each case so 
radically differs from all other cases that an appliance must be invented 
and constructed from raw material to meet its special requirements. 
The second plan recognizes the division of malocclusion into a few 
clearly defined classes, having requirements of treatment clearly indi- 
cated, with fixed, standard forms of ready-made regulating appliances 
acting upon definite principles, which amply provide for the require- 
ments of all cases belonging to each class. 

The first, until the introduction of the writer's appliances, was the 
universal plan, having come down to us from the earliest history of 
orthodontia; indeed, much of the literature of the science consists of 
descriptions of appliances which have been invented to accomplish 
tooth movements in special cases, until some thousands are recorded, 
one author alone boasting of many hundreds. When something may 
be accomplished in the following of this plan, it should require no 
argument to prove that there are many reasons why it is most defective 
and unscientific. 

First, it necessitates that each dentist shall be an inventor, and it is 
well known that the inventive faculty is rather a natural gift than an 
acquirement, and that it can be exercised successfully only by a very 
few. Then, as all inventions if perfected must be experimented with, 
it must follow that each case so treated must be largely in the nature 
of an experiment, often necessitating many changes in the plan and 



740 ORTHODONTIA 

construction of appliances. Hence all treatment upon such theory must 
be, and, in fact, has ever been, tedious and costly, with a large percentage 
of failures. 

Secondly, another objection in following this plan is that the construc- 
tion of appliances must necessarily be more or less crude and lacking 
in requisite proportions, for any instrument only reaches perfection as to 
size, proportion, temper, strength, and finish after much experimenting 
and repeated efforts toward perfection in manufacture. 

Finally, another objection more serious than all is that as the plan 
is empirical, with only a vague and indefinite basis from which to reason, 
the difficulties in teaching and practice become very great and the 
results greatly limited. After a life of practice the dentist following 
this plan must still be in a maze of experiments, and unable to impart 
much information that could be of assistance to those who may begin 
practice after him. 

The second plan, as we have already stated, recognizes the practi- 
cability of fixed, standard forms of devices for the requirements of 
tooth movement necessary in all the various classes of malocclusion, 
the proper forms having been arrived at as a result of careful experi- 
mentation and close observation in a very large number of cases em- 
bracing the greatest variety of malocclusion. Instead of hand-made 
productions by the dentist, which, with his limited experience and meager 
facilities, must always fall far short of the ideal, they are, like fine watches, 
made upon elaborate machinery by the most skilful workmen. 

If such appliances are practicable, it must at once become apparent 
that the advantages from their use must be very great, for, instead 
of being confronted with a confusing and almost limitless number of 
devices, which can at best only serve as general, vague, and often delusive 
patterns to him, the student has but to thoroughly familiarize himself 
with a few standard devices which he may quickly and easily apply. 

Again, familiarity with and repeated use of standard appliances add 
greatly to the possibilities of development of skill and judgment in their 
use, as in the case of the frequent use of favorite patterns of pluggers 
or excavators which have also been made by skilled experts. And 
whether or not ideal standard regulating appliances have yet been reached, 
the possibilities and positive advantages of the principle over that of 
the first plan are so marked that we think all teachers who are inter- 
ested in this branch should make effort toward that direction, rather 
than to assist in perpetuating a principle so obviously defective that it 
must be apparent to all that it is a positive hindrance to the real progress 
of orthodontia. 

It is now well known that most of the real progress in dentistry and 
surgery, and, we may add, in orthodontia, has been made since the 
dentist, surgeon, and orthodontist were relieved of this impractical 
task by experts who have produced instruments so perfect in design, 



REGULATING APPLIANCES 741 

construction, and finish as to be often in advance of the comprehension 
and skill of those who are to use them. 

Materials for Construction. — A large number of materials have been 
used in the construction of devices for the regulation of teeth. Gold, 
silver, platinum, platinous gold, platinous silver, iridioplatinum, 
platinoid, aluminum, nickel silver, brass, copper, aluminum bronze, 
steel, iron, vulcanized rubber, India rubber, wood, silk, hemp, gut, and 
many combinations of these materials have all been used. None are 
ideal, yet most of them possess properties of more or less value. After 
years of experimenting the writer is convinced that the material most 
nearly filling all requirements is high grade nickel silver. 1 

Since its introduction by the writer, in 1887, 2 for the construction of. 
regulating appliances, it has largely supplanted all other metals for 
this purpose. Owing to its excellent qualities, as well as its inexpensive- 
ness, nickel silver has been an important factor in the remarkable 
progress that orthodontia has made in recent years. Its great practical 
value becomes more and more apparent with familiarity in its use. It is 
very susceptible of skilful working, and may be developed to possess 
great strength and rigidity, or it may be given great elasticity, and when 
properly annealed it is very malleable. Rolled into a flat ribbon, it may 
be drawn by the band-forming pliers so tightly about a tooth as to con- 
form to its surface with great accuracy, on account of its properties 
which permit of slight stretching, in striking contrast to gold or platinum, 
and even though it be but three-thousandths of an inch in thickness, it 
will be sufficiently rigid to withstand driving to place upon the tooth 
without crimping or changing form, if care be used. 

Its surfaces are readily united by solder, and its fusing-point is so 
high that any of the various grades of gold or silver solder may be 
employed without injury to the band if only the requisite amount of 
heat be used. 

It is so slow a conductor of heat that the excellent method of soldering 
by holding many of the pieces with the fingers may be employed, 3 
again in sharp contrast to the other metals we have enumerated. 

It is susceptible to a high degree of polish, which should always be 
given to plain bands after setting, and which is lasting in many mouths. 
Often these bands will assume a delicate bronze-like color, pleasing in 
appearance, and the writer has known of their being worn continuously 
for three years with no change of color. In a small percentage of mouths, 
however, they do become discolored, even to unsightliness. This fact 
has given rise to the only worthy prejudice we know of against the use of 

1 Nickel silver is an alloy of copper, nickel, and zinc, prepared in varying pro- 
portions, according to the use for which it is intended. The inferior grades con- 
tain iron and only a low percentage of nickel. 

2 Angle, Archives of Dentistry, 1888. 

3 Introduced by the writer in the first edition of his work entitled the Angle 
System of Regulation and Retention of the Teeth. 



742 ORTHODONTIA 

nickel silver for regulating appliances; but this objection is trivial in view 
of its many points of superiority and if the orthodontist will use the proper 
quality of nickel silver and obey the demands of modern prophylaxis, 
insisting on a reasonable degree of cleanliness on the part of the patient, 
and occasionally devoting a few moments of attention to the cleansing 
of appliances and teeth himself with the soft-rubber disk and pumice, 
as he should, no matter what metal is used for the appliances, there 
will be little occasion for complaint. 

Another valuable property of nickel silver is that it is less liable to 
injure the enamel of teeth when worn in contact with it, than are any 
of the precious metals. 

Notwithstanding the valuable qualities of nickel silver, the precious 
metals, as gold, platinum, and iridium, are still preferred by a few practi- 
tioners on account of their greater resistance to oxidation. Yet they are 
by no means free from this fault, as it is necessary to alloy them with 
base metals in order to gain the proper elasticity. Yet when properly 
alloyed they are sufficiently free from oxidation for the necessary use, 
and it is probable that in some mouths, for appearance' sake, they are 
more desirable than nickel silver, especially as retaining devices that 
are to be worn a long time upon the teeth. 



THE WRITER'S APPLIANCES 

When the writer first brought out his so-called system of appliances, 
malocclusion was yet unclassified, and the "special appliance for each 
case" method of treatment was the only one taught or practised. In 
an attempt to reduce to something like system and order the chaos of 
regulating appliances that cumbered the literature and hindered the prog- 
ress of orthodontia, these appliances, designated as sets Nos. 1 and 2, with 
a few auxiliary parts, numbering some twenty in all, were introduced. 

By their use separately and in combinations it was presumed, and 
truly, that tooth movements could be much more quickly and easily 
performed, and with far less annoyance to the patient, than by means 
of the necessarily crude, clumsy, and frequently very inadequate hand- 
made metal devices, or the far more undesirable and most unclean vul- 
canite plates, cribs, etc. With the greater development of the science, 
however, and especially since the classification of malocclusion, the 
writer has gradually dispensed with the greater part of even these few 
appliances, until at the present time he uses practically but one, or three 
modifications of a single principle. This principle was given us nearly 
two hundred years ago by the famous French dentist, Fauchard, 1 and it 
has since been used in many modified forms. It is now known as the 

1 Le Chirurgien Dentiste ou Traite des Dents, Paris, 1728. 



THE WRITER'S APPLIANCES 



743 



expansion arch, and in conjunction with clamp-bands for the anchor 
teeth, and the auxiliaries of plain or spurred bands, and wire and rubber 
ligatures, it is adequate for all necessary movements of all teeth in each 
arch separately, as in Class I cases, or for the simultaneous movement 
of all teeth in both arches when used in connection with the Baker 
anchorage, as in cases belonging to Classes II and III. 

The writer's improvements of this appliance may briefly be said to 
consist in change of metal (nickel silver), modification of form and pro- 
portions, delicacy of temper, greater length of threading of sides for 
universal adjustment of size, in the material, original patterns, and pro- 
portions of the anchor clamp-bands, and in the various attachments, 



Fig. 759 




some of which are modified and others newly devised. Important 
among these is the addition to the clamp-bands of the long tubular sheaths 
for the reception of the ends of the arch, which not only protect the 
cheeks from abrasion by the threaded portion of the arch, but give 
greater stability to the anchorage. Still others deemed very important 
are the friction sleeve of the sheath of the clamp-bands and extension 
flange of the arch nuts, the extension rib on the ribbed arch, the sheath 
hooks, for use in the Baker anchorage, and last and most important, the 
brass-wire ligatures, descriptions of all of which follow, in connection 
with instructions for their use. 

As before stated, there are three forms of the expansion arch. Fig. 
759 represents the plain expansion arch E, which is a very elastic round 



744 



ORTHODONTIA 



bar, bent to conform approximately to the shape of an ideal dental arch. 
The sides of this arch are threaded and provided with nuts, which, with 
the threaded portion of the arch, accurately fit the smooth-bore tubes of 
the X and D bands. One end of these nuts is elongated to form an 
extension flange, which accurately telescopes the friction sleeve of the 
sheaths of the D and X bands, as shown in the engraving. 

This form of nut adds another truly valuable improvement to the ex- 
pansion arch, as it enables us to make the exposed part of the nut very 
short and compact, at the same time giving greater length of thread 

Fig. 760 





and consequently greater strength. Its greatest value, however, is that 
this extension flange prevents the loosening of the nut by unscrewing 
from friction with the tongue or cheek — a common annoyance since 
screw devices have been used in the mouth, and for this purpose it is 
ideally simple and efficient. This improvement is also made use of 
in the writer's jack- and traction-screws. 

Fig. 760 shows the ribbed expansion arch E, a later modification of 
the arch last shown, and differing from it only in that it is provided with 
a delicate rib on the periphery of the unthreaded portion, in which hook- 
like notches are to be made at desired points to prevent slipping of the 



THE WRITER'S APPLIANCES 



745 



wire ligatures. By this means the direction of force on the moving teeth 
is accurately controlled. The rib also adds force to the arch for lateral 
expansion. It is a most important improvement. 



Fig. 761 




Fig. 761 shows the third form of the arch, as used by the writer, 
known as the arch B. It is a smooth, threadless arch, similar in form 
and temper to the plain expansion arch E, though more limited in use. 
It is especially designed for use in connection with the Baker anchorage, 
having a sheath-hook on each side for the reception of the rubber liga- 
tures. 

Fig. 762 



la 



These little sheath-hooks, Fig. 762, may also be obtained separately 
for attachment to either of the other arches whenever it may be desired 
to employ them in connection with the Baker anchorage. 



Fig. 763 




Fig. 763 represents six adjustable clamp-bands. Nos. 1 and 2 are 
plain, and are used both for tooth movement and in retention. Nos. 
3 and 4 are provided with strong-headed pins soldered to their screw- 
heads. These were especially designed for the treatment of fractures of 
the maxillae. 1 



1 For a consideration of this subject the student is referred to the sixth edition of 
the writer's work on Malocclusion of the Teeth and Fractures of the Maxilla?. 



746 



ORTHODONTIA 



The X and D bands are provided with smooth-bore tubes soldered 
to their sides, into which the ends of the arches and the extension flange 
of the nuts accurately fit. The X bands are for bicuspids and the D 
bands for molars. 1 

Fig. 764 shows three coils of band material from which plain bands 
for incisors, canines, or even premolars may be made, to serve as mediums 





of attachment to the arch through the wire ligatures. They also are 
very largely used in retaining devices. C and F are of the same width, 
being narrower than H, and F and H are of the same thickness, being 
thicker than C. C is used only when a very thin, delicate band is 
required. F is used where a stronger band is needed, and has much 
more universal use. H is used principally for canine bands. 

Fig. 765 




Fig. 765 represents the wire G, a section of very soft, smooth wire. 
For the making of spurs on bands for the attaching of ligatures, or for 
retention, it is indispensable. It is also used for reinforcing anchorage, 
and for the moving of teeth in a novel way, the latter being illustrated 
in Fig. 829. The size of this wire to be most universal of use was 



1 For the varying sizes of molar teeth are three sizes of D bands, although in 
the writer's practice the medium size alone meets nearly all requirements of the 
permanent molars. The smaller size, however, is occasionally demanded on de- 
ciduous molars. 



THE WRITER'S APPLIANCES 



747 



decided upon, after much thought and experimenting, to be forty-two 
thousandths of an inch in diameter. Yet for the making of smaller 
spurs, and, occasionally, later forms of retaining devices, a wire of 
smaller diameter has proved advantageous. So the writer has recently 
added two smaller sizes, one twenty-nine thousandths of an inch in 
diameter and the other twenty-two thousandths of an inch in diameter. 
These are both of precious metal. 



Fig. 7( 



/ 



Fig. 766 represents the retaining tubes R, which are used in detach- 
able connections, in reinforcing anchorage, in retention, etc. 

Fig. 767 represents the brass ligature wire, which is very soft, smooth, 
tough, strong, bright wire, especially prepared for the use of orthodon- 
tists. Three sizes meet all requirements. 



Fie. 767 




Fig. 768 represents strips of rubber used by stretching between 
tooth and arch, or between ligature and tooth, then cutting on* the super- 
fluous ends, as in Fig. 80S. In this way force is made more continuous 
and the time for tooth movement shortened. In like manner the strips 
of rubber are used with great advantage to assist in rotating very obstinate 



Fig. 768 



I Q U G 



3/I6IN. WIDE 
llll 



teeth, as shown in Fig. 769 and 770. The figures just referred to and 
Fig. 807 all show working combinations of the writer's appliances just 
described. 

The following appliances are those which the writer has now practi- 
cally eliminated from his practice, not because they were inefficient to 



748 



ORTHODONTIA 



perform the tooth movements required of them, but because they were 
designed to act locally, so to speak, or only upon teeth that seemed 



Fig. 769 




E. H. A 



"crooked," instead of to operate from the basis of occlusion, and having 
control of one tooth or of all teeth in one or both arches. But, as will 



Fig. 770 




be shown later, while not often used, they are still so necessary for 
some purposes that they cannot be wholly dispensed with. Their uses 
will be described later. 



THE WRITER'S APPLIANCES 



749 



Fig. 771 shows the jack-screw E and J. The first regulating jack: 
screw was invented by Dr. Dwindle, of New York, in 1848. Thi- 
invention marked two important steps in the progress of this sciences 
(1) The introduction into orthodontia of one of the most compact yet 



Fig. 771 




powerful forms of mechanism known to mechanics for exerting force; 
(2) the beginning of fixed, standard forms of regulating appliances, 
with interchangeable parts, and kept in stock at the dental supply 
houses. 1 



Fig. 772 



■it 



^ 



Fig. 772 shows the traction-screw A and D. It consists of a shaft 
bent sharply at right angles at one end, the other end threaded and 
provided with an extension flange nut and three accurately fitting tubes 



Fig. 773 




of smooth bore — one long one with friction sleeve for the accommoda- 
tion of the extension flange of the nut, and two short ones, D. Since 
in treatment the sacrifice of teeth has become rarely necessary, the 



Fig. 




use for this once highly regarded appliance is greatly limited, yet it 
is still valuable on rare occasions. 



1 The writer's jack-screw was invented in 1886. Transactions Ninth Inter- 
national Medical Congress. 



750 



ORTHODONTIA 



Fig. 773 shows a bundle of spring levers, of four different sizes. 
These are made of piano wire, on account of its superior elasticity; 
yet because of the liability of steel to corrode, no matter how heavily 
plated, its ordinary use is objectionable. These levers may also be 
made of nickel silver or of a combination of gold and iridioplatinum. 



Fig. 775 




The traction bar A, Fig. 774, is provided with a standard in its centre, 
which has a socket for the reception of a delicate ball on the centre 
of the arch B. The hooked ends of this bar are for the reception of 
heavy elastic bands from the headgear, as shown in Fig. 775. 

The headgear, Fig. 776, is a cap of silk netting laced to a metal rim 
and covering the back of the head, for the even distribution of force 



THE WRITER'S APPLIANCES 



751 



exerted by the heavy elastic bands. This cap is strong, artistically 
made, and is very neat in appearance. The rim is non-collapsible and 
may be easily and quickly adjusted to fit any size of head. 



Fig. 776 




E.H.A 



The traction bar and headgear still embrace the best principles in the 
application of oc^pital anchorage, but in their use the relinquishment 
and reapplication of pressure is necessarily frequent, and this is always 
an objectionable feature, being the most potent cause of inciting inflam- 
mation in tooth movement. So it is for the best of reasons that they 



Fig. 777 




have largely given place to the more rational method of applying force 
by means of the Baker anchorage. They cannot yet be wholly dis- 
pensed with, for it is occasionally very advantageous to apply force in 
this way as auxiliary to the Baker anchorage. 



752 



ORTHODONTIA 



The chin retractor, Fig. 777, is made of aluminum; it is light, neat, and 
highly polished. It will fit in all cases, as it is only necessary that the fit 
be approximately accurate. A layer of fresh absorbent cotton should 
always be placed between metal and chin each time it is adjusted. 



Fig. 778 Fig. 



Fig. 780 



Fig. 781 




Used with the headgear, as shown in Fig. 777, it was formerly our chief 
reliance for the treatment of cases belonging to Class III, but its use, 
also, has been practically superseded by the Baker anchorage, yet it 
will doubtless continue to be a valuable auxiliary to the Baker anchorage 



m rare cases. 



THE WRITER'S APPLIANCES 



753 



Tools. — For uniting the different parts of the appliances to form 
the various combinations, and for placing them in position upon the 



Fig. 782 



Fig. 783 





Fig. 7S4 




teeth, only a few tools are necessary, but it is important that they should 
be of the best selection and some of them of special design. 

Fig. 778 shows the writer's soldering pliers. Their delicate proportions 

48 



754 



ORTHODONTIA 



and peculiar form make them especially suited for holding bands while 
soldering, as well as other pieces of the appliances. 

Fig. 779 shows another pair of pliers, for placing pieces of solder in 
position, picking up small pieces, etc. 



Fig. 785 



Fig. 786 





The writer's band-forming pliers are shown in Fig. 780. These 
were designed especially and are indispensable for band-making. They 
also are very useful for most other purposes for which ordinary flat- 
beaked pliers are used, and are provided with grooves for holding the 
small square nuts and round wire. 



THE WRITER'S APPLIANCES 755 

A good pair of wire cutters is essential. The style shown in Fig. 
781 is the most satisfactory of the many makes that the writer has tried. 

The writer's regulating pliers are shown in Fig. 782. With them any 
necessary degree of force may be applied for the movement of teeth in 
a novel manner, illustrated in Fig. 783. In no other way, not even 
excepting the wedge, is force exerted in so compact a manner, and yet 
the degree of force is under the most perfect control. 'While the range 
of application of this method of applying force is not great, yet on account 
of its simplicity it is extremely valuable in widening the anterior part of 
the arches of very young children, as shown in the illustration. 

A section of wire which has been softened and pointed at each end 
is made to rest in pits in the enamel of the deciduous canines. The 
movement of the teeth is effected by lengthening this wire by an occasional 
pinch from the regulating pliers. These pliers should never be used 
on hard wire. 

This instrument is also valuable in many other ways, especially in 
modifying the form of retaining devices without the necessity of their 
removal. 

The flattened portion of the very powerful beaks make it ideal for 
giving temper to softened wire through slightly flattening the wire. 

The writer also uses it with much satisfaction as a hand vise. 

Decidedly the most convenient form of scissors for trimming bands, 
clipping ligatures, etc., is shown in Fig. 784. 

The How pliers, for twisting ligatures and for general uses, is shown 
in Fig. 785. 

An ordinary hand mallet and band driver (shown in Figs. 786 and 
787) are also requisite. The flat end of the band driver, as here shown, 
has too long a bevel. It should be shorter and more nearly at right 
angles, so as not to cut the bands, and occasionally roughened with a 
fine file to prevent slipping. The round end is for restoring the form 
to the ends of the tubes of the anchor bands when accidentally bent. 

The two wrenches shown in Figs. 788 and 789 are of universal appli- 
cation to all the various nuts of the appliances ; one, a single-end wrench, 
and the other a double-end, or right-and-left, wrench especially designed 
for the adjustment of nuts of the clamp-bands on lower molars, they 
being practically inaccessible to the use of a straight wrench. Both 
are made of steel, nickel-plated, and finely finished. 

And very important is a suitable blowpipe for soldering. The 
writer prefers the one shown in Fig. 790, the invention of a former 
student of his, Dr. Jos. Griinberg. It has a very delicate flame, and 
may be quickly adjusted to any desired angle or height. 

Dr. Oppenheim, also, has added another useful tool to those already 
enumerated, for use in connection with the writer's appliances. It is 
illustrated in Fig. 791, and is for the purpose of grasping a screw or 
piece of wire and firmly holding it at any desired angle while it is 



756 



Fig. 787 



;■ 



ORTHODONTIA 

Fig. 788 




Fig. 789 





Fig. 790 




SOLDERING 



757 



being soldered or filed. Fig. 792 shows a finely tempered steel instru- 
ment devised by Dr. Griinberg, that has been turned to exactly fit the 
bore of the friction sleeve of the tubes of the X or D bands — very 
useful in effecting the proper alignment of these tubes when fitting 
the bands to the teeth. 



Fig. 791 



Fig. 792 




SOLDERING 



It is safe to say that no one will ever attain proficiency in orthodontia 
unless he acquires much skill in soldering, for the soldering of bands 



758 



ORTHODONTIA 



and the union of tubes and spurs to bands is of such frequent necessity 
that skill in the work is highly essential. Efforts have been made by 
some to construct regulating and retaining appliances so that all unions 
of parts shall be effected by mechanical attachments, as screw-, hook-, 
or clamp-joints. But to the thoughtful observer it would require no 
argument to prove that such attachments, beyond certain narrow limits, 
are impracticable, and that a brazed joint is far stronger, far more 
compact, cleanly, and inexpensive. 

As many of the parts of these appliances are very delicate, it is important 
that a fine, sharp, steady flame be used in effecting their union by solder. 
A large or uneven flame would injure and might ruin them. The blow- 
pipe should be operated with the ordinary foot bellows, or automatic 
compressor, leaving the hands of the operator free. 



Fig. 793 



Fig. 794 





The plan of soldering introduced by the writer in 1887, of holding the 
pieces in contact with each other, in the flame at the desired point with 
the fingers or pliers, avoids completely the time and trouble necessary 
for investing the pieces, or wiring them together, as formerly. The 
metal of which these appliances are made is most favorable for solder- 
ing in this way, it being so poor a conductor of heat that most of the 
attachments can be held in the fingers without any perceptible com- 
munication of heat to them, provided the flame is suitable. 

When union of a small tube with a band is desirable, as in Fig. 793, 
the tube is best held in contact with the band and flame by means 
of some delicate instrument that will absorb but little heat. One of 
Gates' nerve drills with the point broken off is nearly ideal for this 
purpose. When two small tubes are to be united, as in Fig. 794, pliers 
may be used for supporting one of them. 

This method of soldering is not difficult, most students learning it 
readily. The only point that may seem at all difficult to the beginner 
is the holding of the pieces in fixed position just at the time the solder 
is congealing. This is accomplished by touching one or more of the 



SOLDERING 759 

fingers of one hand with those of the opposite hand, as in Figs. 793 
and 794, to steady them, at the same time holding the pieces gently, not 
rigidly, just as a good penman holds a pen. After a little practice 
any of the various soldered attachments may be easily and quickly 
made. 

When the end of a small tube is to be united to a band, it is best to 
fuse the solder upon the band, then hold the small tube by means of the 
straight pliers in contact with the solder and again apply heat, as other- 
wise the solder will usually be drawn into the tube. 

The solder best adapted for uniting the different parts of these appli- 
ances is silver solder, 1 although any of the various carats of gold solder 
may be used with cream of borax for a flux. Never use more solder 
than is necessary, especially in all small attachments — just enough to 
make the union. 

Always avoid overheating. Apply just sufficient heat at the right 
point from a fine, sharp flame to thoroughly fuse the solder. In every 
instance avoid heating the screws or nuts. This is to be especially 
observed with the jack- and traction-screws and the arches E and B, as 
great care is used in their manufacture to preserve their elasticity and 
strength, and this fine temper would be ruined by heating. 

Almost innumerable clamps and springs have been devised for hold- 
ing the pieces while soldering, many of them complicated and bulky. 
They are entirely useless to him who will devote a little time to mastering 
the plan of soldering above outlined. 

Making Plain Bands. — As the plain bands form such an important 
part in this system, it is important that proper methods be employed in 
their making. 

We have already stated our reasons for preferring nickel silver for 
the making of regulating appliances, and especially for the making of 
bands; yet this metal varies greatly in quality, not only on account of 
differences in the formulse from which it is made, but also on account 
of the manner of manipulation in manufacture. 

It is important that it shall be of the proper fineness, thickness, and 
temper, or it will be harsh and unyielding and difficult or impossible of 
proper adaptation to the form of the tooth, in which case it will loosen 
more readily under the strain of tooth movement, will occupy unneces- 
sary space between the teeth, and present a less pleasing appearance. 

There is a chance for the development of real skill in the making 
and fitting of plain bands, and no one can do it successfully without 
devoting time and study to the technique of the operation. 

Let it be remembered that each coil of band material must first be 
annealed in bulk, by heating it to a dull redness, before breaking the 

1 The writer recommends a silver solder for the use of orthodontists by the S. S. 
White Dental Manufacturing Co. Dr. Griinberg has recently advised that for con- 
venience the solder be drawn into the form of wire — about 18 gauge. 



700 



ORTHODONTIA 



wire encircling it. Then, to simply pinch a short piece of band material 
about the tooth is to make a loose, crude fitting band, Fig. 796. Pieces 
of generous length should be used and the band made over the natural 
tooth, not over a plaster tooth. 

Another point of great importance is that the band, in order to fit 
perfectly, must be stretched about the tooth in the making. This can 
only be accomplished by slipping the loop of band material around 
the tooth to the desired point, pulling firmly on the ends of the band 
material in one direction with the thumb and fingers of one hand, while 



Fig 




the band-forming pliers are pushed with equal force in the opposite 
direction at the same time they are closed in the act of pinching the 
ribbon of metal about the tooth with the other hand. 

By this method sufficient pressure is brought to bear to make it fit 
with the greatest accuracy the surface of the tooth around which it is 
drawn, and if after soldering the surplus ends be cut off so they will still 
be united, as in Fig. 795, there will be very little waste to the strips of 
band material, and ample length for a firm grasp will always be insured. 
By exercising the proper care a considerable number of bands can be 
made from each of the coils of band material C, F, and H. 



Fig. 796 





No one should expect other than a very crude band if rough or loose- 
fitting pliers be used for pinching, for the junction of the pinched por- 
tion will then be rounded, as in Fig. 796, instead of sharp and at right 
angles, as in Fig. 795. 

In soldering a band a portion of silver solder about one-eighth of an 
inch square, wet with borax cream, is placed between the angles of the 
band and held, by means of the band-soldering pliers, over the flame, 
Fig. 797. With these pliers uniform pressure is exerted at the exact 



SOLDERING 



761 



points necessary to insure the seam being even and perfect, while the 
minimum amount of heat only is absorbed by the pliers; consequently 
no change of form or injury to them is likely. A further advantage of 
their use is that their points rest in contact with the band material in 
such position as to be shielded from the solder, so that none will be fused 
upon its points, thus avoiding an annoyance of no small moment that is 
often encountered in the use of ordinary pliers, their contact with the 
solder being almost a necessity. 



Fig. 797 



SOLDER 




To insure the flowing of the solder in the seam only, plenty of borax 
should be placed there, but none on the inner surface of the band, as 
otherwise the solder will be drawn from the seam and there will be 
faulty union or a thickening of the band, either of which would render 
it entirely useless. When soldered the band should present a continu- 
ous, even inner surface. Any other union is imperfect and is ample 
cause for condemning the band. The band being properly fitted, it is 
ready for any attachments which may be required. 




Fig. 798 



© O Q ^ 




Let us again insist upon the importance of a very hot, fine, sharp- 
pointed flame in the making of all these attachments, as neatness in 
such delicate soldering is impossible with a coarse flame. 

The principal soldered attachments to the plain bands are tubes R, 
spurs, and staples. The two latter are made from the wire G, as shown 
in D, E, G, and H, Fig. 798, and B, Fig. 807. 



762 



ORTHODONTIA 



The attachment of a spur is best accomplished by heating the smoothed 
end of the wire G, touching it to a large piece of borax, and holding it 
in contact with a small piece of solder in the flame until it is partially 
fused, then bringing it in contact with the band at the desired point and 
again holding it in the flame. After it is fused (Fig. 799) it is clipped 
off to the desired length, which should never be but slightly greater than 
the diameter of the ligature which is to engage it, and the roughened 
ends made smooth with a file. But little solder should be used, as 
a large amount would form an incline, which would not so well hold 
the ligature. 

If a staple is to be made, the end of the wire is bent into the form of 
the letter U, the solder is flowed upon the surface of the band first, then 
the convex portion of the staple is held in contact and the solder re-fused, 
after which the ends are clipped to about one-sixteenth of an inch 
in length and smoothed with a file, as in E and H, Fig. 798. The jaws 
of the staple should closely fit the piece they are to engage. 



Fig. 799 




When an oval loop, as in D and G, Fig. 798, is to be attached, the 
solder should be flowed first upon the band, and only in sufficient 
quantity to secure the loop at the given point. A larger amount is 
unnecessary, and might be drawn into the cavity of the loop. 

It is desirable that all attachments, both for moving the tooth and in 
anticipation of retention, shall, if possible, be made before first setting 
the band, in order that the pain and trouble of removal and substitution 
of a new band, after the teeth have become tender, may be avoided. 

The untrimmed ends of the band serve the useful purpose of a handle 
for holding it in the flame and in contact with the piece to be attached, 
as in G and H, Fig. 798, and Fig. 799. After the attachments have 
been made the ends of the bands are trimmed off, leaving them long or 
short, as desired. If a niche is to be formed to engage some other appli- 
ance, the ends are left about one-sixteenth of an inch long, as in A, Fig. 
798; but if they are not to serve as a means of attachment they may 
be trimmed still shorter, although it is never desirable to trim them even 
with the surface of the band. The sharp corners should be rounded. 



SOLDERING 763 

The canine is the most difficult of any of the teeth to band, but by 
forming the seam on the lingual incline instead of on the labial, and 
firmly burnishing the outer surface while it is being pinched, an accurate 
fit can in most instances be made. Another plan is to pinch a fold in the 
loop of band material on the lingual incline, while the ends of the band 
material of generous length are being firmly drawn with the fingers on 
the labial side. The band is then removed and a little solder flowed 
into the fold. It is then replaced on the tooth, and the seam made upon 
the labial surface in the usual way, as described on page 760. While 
it is slightly more difficult to make a band by forming the seam on the 
lingual surface of the tooth, yet its appearance is much neater than 
when the seam is made on the labial surface. It is decidedly easier to 

Fig. 800 




make and fit bands made of nickel silver than those made of the more 
unyielding alloys of gold, iridium, and platinum. Yet, as it is some- 
times necessary to make them of the latter, it is highly important that 
the proper skill be developed for their proper making and fitting. 

Soft-soldering. — It is frequently necessary to attach sheath-hooks to 
the arches E, which are manufactured in such a way as to give them the 
greatest possible amount of spring. If the sheath-hooks are attached by 
means of the ordinary soft solder with which they come provided, the 
temper of the arches will not be injured, provided only a small, passive 
flame be used, with just sufficient heat to melt the low-fusing solder. 

It is sometimes desirable to attach spurs to the plain arches E or the 
arches B, to prevent the slipping of the wire ligatures, although since the 



764 ORTHODONTIA 

introduction of the ribbed arch this necessity is largely obviated. When 
spurs are used they should be attached by means of soft solder, in order 
not to injure the spring of the arches. 

The best plan for making these spurs is to fuse a very small piece of 
this solder upon the end of a section of ligature wire (first having dipped 
the end of the wire in soldering fluid), then holding it in contact with 
the arch in the flame. This gives a fine conical spur with brass centre, 
which is very strong, yet inconspicuous. Fig. 800 shows the arch with 
spurs both before and after the surplus wire has been cut off. The spur 
need be no higher than the diameter of the ligature it is intended to 
support. If higher it will abrade the lips or interfere with their 
movements. 

Jeweller's soldering fluid is used as a flux in making these attach- 
ments. 

For a more full and minute description of the technique of solde ing 
and fitting of appliances to the teeth than is here practicable we strongly 
recommend a most excellent treatise on the subject in pamphlet form, 
by Dr. Jos. Griinberg, procurable from the S. S. White Dental 
Manufacturing Co. 

ANCHORAGE 

Principles of Anchorage. — The correction of the position of a mal- 
posed tooth depends upon two important things: first, that the force 
exerted shall be from the right direction and sufficient to effect the 
movement; and second, that the anchorage shall be sufficient to resist 
this force. 

In the application of force for the movement of teeth, the crowns 
are the only portions available for effecting the necessary attachments. 
Force is usually exerted at right angles, or nearly so, to the long axes 
of their roots, and their changes of positions may be said to be partial or 
complete. 

In the first instance the change is principally in the crown end of the 
tooth, it being tipped into position, thereby changing its angle of inclina- 
tion, with little or possibly no apical displacement. 

In the second case the tooth is moved bodily, its coronal and apical 
displacement being more or less equal, and in the same direction. 

Whether the movement shall be partial or complete depends upon the 
manner of attachment, which determines the distribution of the applied 
force. In the first instance the attachment must be in the nature of a 
hinge or pivot, so as to admit of tipping, as would follow the use of a 
ligature made to exert force practically at right angles to the long axis 
of the tooth. 

To effect the second form of movement necessitates that the attach- 
ment of the appliance to the crown shall be rigid, so that tipping will 
be impossible, the force being then distributed equally to the root. 



ANCHORAGE 765 

Details of Anchorage. — As has before been stated, there are but seven 
distinct malpositions that teeth can occupy. In accordance with the 
laws of physics, their movement into harmony with the line of occlu- 
sion can only be accomplished by the application of force from a fixed 
base of anchorage in one of three ways — pulling, pushing, or twisting. 
As "for every action there is an equal and opposite reaction," it must 
follow that the same amount of force will be exerted upon the anchor- 
age as upon the tooth to be moved, and if the anchorage offer no greater 
resistance than the tooth to be moved, their equal displacement must 
follow. 

For the moving of teeth we have two principal sources of anchor- 
age — first, and chiefly, that which may be derived from the teeth them- 
selves; second, that gained from suitable attachments to the top and 
back of the head. 

The resistance offered by different teeth varies greatly according to 
their positions, size, length, and number of roots, the direction from 
which force is exerted, and also, as we have said, in the manner of mechan- 
ical attachment. 

Of the many modern improvements in the methods of the correction 
of malocclusion, perhaps none have been greater than in the devices for 
securing anchorage. The former bulky and insecure devices for this 
purpose in the form of vulcanite or metal cribs have become practically 
obsolete since the perfection of the plain and clamp bands, which make 
possible much greater control of the anchorage, as well as firmness and 
stability. 

The force should be as direct and positive as may be possible to secure 
with the conditions at our disposal. The ideal anchorage would, of 
course, be that from an immovable base. This, however, is probably 
never fully possible in the mouth, owing to the slight spring of the alve- 
olar process and cushion-like function of the peridental membrane. 
Some displacement of anchor teeth is admissible, and even sometimes 
desirable, provided they be kept within the limits of final restoration by 
means of the inclined planes of the occluding teeth; but if greater dis- 
placement than this take place, malocclusion of the anchor teeth, most 
difficult or even impossible to overcome, may be established. Hence 
they should be closely watched and careful measurements and com- 
parisons with the original models be frequently made. Any unfavorable 
movement perceived should be promptly combated. The embarrass- 
ment following any considerable displacement of the anchor teeth is 
so serious that ample anchorage should always be secured in the 
beginning. 

The available anchorage may be said to be of five kinds. They are 
more or less intimately associated, and are used in combinations or sepa- 
rately, according to the exigencies of requirement. We will designate 
them as simple, stationary, reciprocal, occipital, and intermaxillary. 



766 



ORTHODONTIA 



Simple anchorage is that form in which the resistance of the moving 
teeth is overcome by means of an anchor tooth or teeth of larger size 
or more favorable location, the form of attachment being hinged or 
pivotal, admitting of the tipping of the tooth to be moved, and the possible 
tipping of the anchor tooth. This form of anchorage, although often pri- 
marily unreliable in itself, may be reinforced by enlisting the resistance 
of other teeth in the same arch, near or remote in location. 

Stationary anchorage 1 is that form in which the attachment to the 
anchor tooth is essentially rigid, so that its tipping is impossible, and 
if moved at all it must be dragged bodily through the alveolar process 
in an upright position. Fig. 801 shows an illustration of stationary 
anchorage to a molar in the retraction of a canine. The long sheath 
of the screw is soldered to a clamp-band rigidily cemented and clamped 
upon the molar, while the angle of the screw engages a tube soldered 
horizontally to a plain band on the canine. The attachment to the 



Fig. 801 



Fig. 802 





canine is hinged and designed for tipping. Should any displacement 
of the molar occur, both root and crown would be moved equally and in 
the same direction. It will thus be seen that the resistance in this form 
of anchorage is vastly greater than in the simple form. 

Skill and judgment are necessary in the use of this form of anchor- 
age, for its success depends, first, on the absolute rigidity of the attach- 
ment and appliance to the anchor tooth, and second, on the amount 
of force exerted, which must not at any time be so great as to impair 
the rigidity of the appliance or attachment. This is of vital impor- 
tance, for any loosening or straining of the attachment would partially 
or completely change the anchorage from stationary to simple. 

Reciprocal anchorage, strictly speaking, is not a distinct form of 
anchorage, yet its value and possibilities in application are such that it 
may with propriety be so regarded. It is that form in which one malposed 



Angle, Items of Interest, December, 1887. 



ANCHORAGE 



767 



tooth is pitted against another in the same arch, the tendency of the 
force, correctly applied, being to move both into the line of occlusion. 

Reciprocal anchorage admits of the widest range of application and 
is the most valuable form of anchorage. Each case should be studied 
carefully with a view to its use whenever possible, either in its simplest 
forms, as in Fig. 802, or when a greater number of teeth are to be moved, 
as in widening the arch (Fig. 811), or in combination with other forms 
of anchorage. It will be found applicable to a very large percentage of 
cases, and is an important principle in many of the combinations 
of appliances to be hereafter shown. 

Occipital anchorage is that form in which the resistance is borne 
by the top and back of the head and transmitted by means of the head- 
gear and heavy elastics to attachments upon the teeth, as in Fig. 775. 
This well-known form of anchorage, heretofore principally applicable 
in the treatment of cases belonging to Division 1 and its subdivision 
of Class II and to Class III, has, since the development of intermaxil- 
lary anchorage, been largely superseded by it. 



Fig. 803 



Fig. 804 





Intermaxillary anchorage is a new form of anchorage, differing from 
those already described in that the anchorage or resistance to the moving 
teeth is derived from the teeth of the opposite arch. It may or may not 
be used reciprocally. 

Figs. 803 and 804 illustrate this form of anchorage in cases in which 
it is not used reciprocally, the elevation of the upper canines being 
accomplished by means of rubber ligatures attached to devices on the 
lower teeth, and the lower teeth prevented from elevating by the irre- 
sistible pressure of occlusion. 1 

Fig. 893 shows a remarkable case which this anchorage was made 
to act reciprocally in forcing the elevation of both upper and lower 
incisors, canines, and premolars. This form of anchorage is direct and 
powerful, and may often be employed to much advantage. Its impor- 
tance in the modification now known as the "Baker anchorage" is so 
great as to mark an epoch in the evolution of orthodontia, for with it 



1 This form of anchorage was introduced by the writer. 
1891, p. 743. 



See Dental Cosmos, 



768 



ORTHODONTIA 



the entire plan of treatment of cases belonging to both Classes II and 
III has been revolutionized, and instead of the movement of the teeth 
in these cases being difficult, as formerly, these cases have become, 
by the correct application of this form of anchorage, among the easiest 



Fig. 805 




and most satisfactory that we are called upon to treat; that is, if taken 
at the proper age and intelligently managed. This form of anchorage, 
as used by Dr. Baker, is shown in Fig. 805, and as improved by the 
writer is shown in Fig. 806. 1 



Fig. 806 




ADJUSTMENT AND OPERATION OF APPLIANCES 

Normal occlusion is now recognized as the working basis 2 of ortho- 
dontia, and since this recognition has necessitated not only the diagnosis 
of malocclusion and the art requirements from this basis, but prognosis 



1 See Dental Cosmos, March, 1903. ■ 

i Angle, Malocclusion of the Teeth, 6th edition. 



ADJUSTMENT AND OPERATION OF APPLIANCES 769 

and treatment as well. This has made utterly useless many of the 
thousands of appliances appearing in dental literature which were 
designed for the treatment of individual cases from the basis of "align- 
ment" of individual teeth only, regardless of the demands of the entire 
denture from the basis of the normal in occlusion. Obviously, then, it 
would be useless to give here appliances and methods which are now 
obsolete. Obviously, too, it would be useless to give a number of 
modern appliances which are in fact but copies of recognized standard 
forms, differing not in principle, but only in individual matters of 
detail, and differences, too, that often are extremely trivial and that 
very frequently show retrogression rather than progress. 

It has been the constant aim of the writer to reduce the number of 
appliances and to avoid adding those that were unnecessary, well knowing 
that a far greater amount of skill may be developed in the use of a few 
properly formed appliances or tools than is ever possible with a large 
number. This is well known among artisans. It is a matter of regret 
that the literature is again gradually becoming encumbered with instru- 
ments which add nothing to the real progress of orthodontia. 

The appliances and plans of treatment which will be here given 
are such as are now recognized as the standard by all the leading 
orthodontists of this and other countries. 

Like all pieces of mechanism, regulating appliances should be judged 
from the basis of efficiency and simplicity, and an ideal appliance is 
one that, properly operated, would perform all necessary movements, 
whether lingual, labial, mesial, distal, of depression, elevation, or 
rotation, or their combinations, not only with individual teeth, nor of 
the teeth of one arch alone, but all movements required of all teeth 
in both arches, carrying all on simultaneously — one applicable to any 
case of any class, from the simplest to the most complicated in which 
treatment is practicable, and one that should be under the perfect control 
of the operator, who might hasten the movement of some teeth and 
retard that of others, as occasion might require, yet a device so simple 
as to be easily comprehended, and occasion the minimum amount of 
inconvenience to the patient. The writer believes we at last have 
practically all of the requirements we have enumerated in the appliance 
known as the expansion arch, and shown, with its auxiliaries, in Figs. 
769, 807, and 808. 

This appliance is made up of one of the arches E, plain or ribbed, 
or the arch B, anchored to the teeth by means of the anchor clamp- 
bands D or X, and used with the auxiliaries of plain or spurred bands, 
wire ligatures, rubber wedges, and rubber ligatures, according to the 
requirements of the case. This appliance, in slightly varying com- 
binations, is practically the only one now used by the writer. Its great 
value and almost limitless range of possibilities will become more and 
more appreciated in proportion as it is studied and used. 
49 



770 



ORTHODONTIA 



For certain very simple movements of teeth, under suitable conditions, 
other forms of appliances which are made to act locally will be given 
later. 

Adjustment of Clamp-bands. — In adjusting this appliance the first 
step is the fitting of the anchor clamp-bands, either D or X. The use 

Fig. 807 




of the D bands on the first molars is usually preferable, as these are the 
largest and firmest of the teeth, thereby affording the firmest anchorage. 
Occasions may arise, however, in which it may be desirable to adjust 
these bands to the second or third molars. The X bands on the pre- 
molars, used on either one or both sides, may also sometimes be desirable, 
but their use is only occasionally demanded. 



Fig. 808 




E.HA 



In adjusting a clamp-band, the nut should first be loosened suffi- 
ciently to allow ample size for the crown over which the band is to slip. 
The band should then be shaped between the flat beaks of the band- 
forming pliers until it conforms approximately to the shape of the crown 
of the tooth, the shaft of the screw, which should always point forward 
unless for some special reason, being bent also if necessary. The band 



ADJUSTMENT AND OPERATION OF APPLIANCES 111 

should then be worked carefully over iae crown with the fingers and 
made to slide between gum and enamel to the desired point, and then 
alternately clamped and burnished until made to conform accurately 
to the shape of the crown. 

One of the greatest blunders made in adjusting these bands is to 
trim or file the band on its edge in order to prevent supposed interfer- 
ence with the gums. Such procedure only ruins the band. Besides, it 
is essential that this portion of the band shall pass beyond the swell 
of the crown and be clamped and burnished to the neck of the tooth 
to prevent the band from slipping off. This is the most valuable part 
of the band. 

Another blunder frequently made is to begin the clamping or bur- 
nishing before the band is well over the crown. In this case part of 
the band must bear the entire strain, and will be stretched or torn, or 
the band will loosen and come off. 

The screw must not be allowed to project lingually to abrade or 
interfere with the movements of the tongue. The band should be 
turned before clamping until the screw is in contact with the adjoining 
teeth, and after clamping it must still be made to lie in the same position, 
even though it be necessary to bend the screw, as is often required. 

The bands are made to endure the greatest possible strain consistent 
with their nearly ideal proportions. They will, therefore, bear consid- 
erable tightening of the nut, yet if this be carried too far they will be 
broken. It is usually best not to clamp the band too tightly at first, 
but to wait until the second or third sitting for the final clamping and 
burnishing. Clamping of good bands is ample to give all needed firm- 
ness without cementing, except in effecting stationary anchorage, as in 
the use of the traction screw, shown in Fig. 801. Some orthodontists, to 
guard against the possible disintegration of the enamel underneath the 
band, always cement it in position. Now, it is a fact which the writer 
has verified in the use of many thousands of clamp-bands, that the 
danger of injury to the enamel from them without cementing is prac- 
tically nil, especially when they are constructed from nickel silver. 
Formerly he always cemented them, but found that in practice it was 
unnecessary except in cases where there was a noticeable tendency to 
caries in the teeth of the patient. When the band is to be worn but two 
or three months in healthy mouths, it seems to the writer that cementing 
the clamp-bands is a useless procedure. Yet when any doubt exists, 
it is such a simple operation that it is best to follow the conservative 
plan and cement them. In cases where the band is to be worn a long 
time, as in retention, there is then no question as to whether or not 
it should be cemented. Of course, plain, brazed bands should, of 
necessity, be cemented in all cases. 

Fig. 809 shows a D band which has been properly adjusted to the 
crown of a molar. It will be noted that it accurately conforms to the 



772 



ORTHODONTIA 



swell of the crown. A small portion of the upper edge has been bur- 
nished over the distal marginal ridge. This is important to prevent the 
possibility of the band working too far over the crown. A band so 
adjusted offers the firmest anchorage, and cannot be loosened without 
breaking, or unturning the nut. 

If the teeth to be banded are crowded, care and patience are neces- 
sary to work the band into position. This is usually easy with young 
patients, as their teeth admit of considerable movement. The band is 
worked between the teeth on one side first, and allowed to remain for a 
few minutes, then the other side is gently rocked and pressed with the 
ringer, or, better, with a flat piece of wood, until started to place between 
the teeth. It is then well to allow it to rest for a few minutes, after which 
sufficient separation will usually have taken place to readily permit of 
its further adjustment. 



Fig. 809 



Fig. 810 





E. H. A. 



Where space for the band cannot be thus readily made, a very simple 
and efficient way of providing it is by means of the writer's method 
shown in Fig. 810, viz., engaging the approximating surfaces of the 
adjoining teeth with a wire ligature which is tightly drawn and firmly 
twisted and the ends cut off. After twenty-four hours ample space will 
have been gained. 

It is important that the sheath of the clamp band shall be made to line 
accurately with the expansion arch. Usually, with proper care in fitting 
the band, this is easily accomplished. In other cases slight bending of 
the sheath to alignment, with the instrument made for the purpose, 
shown in Fig. 792, is permissible. But if there be any considerable 
variation, as may often be the case, owing to the inclination of the crown 
of the tooth to be banded, the band should be removed and the sheath 



ADJUSTMENT AND OPERATION OF APPLIANCES 773 

resoldered at the proper angle. This is one of the most simple opera- 
tions and the work of but a moment, carrying the band to the flame by 
holding the screw between the jaws of the wire cutters, or with the instru- 
ment shown in Fig. 791, and the ends of the sheath by the angles of the 
band-soldering pliers, all as shown in Fig. 790. In like manner the tube 
may be shifted mesially or distally — an occasional advantage. The borax 
flux must, of course, be applied when soldering. 

Recently it has been suggested that the sheaths of the clamp-bands 
should be self-adjusting by having a pivotal attachment to the bands. 
The utter absurdity of this is obvious, for the band is thus weakened 
and the firmness of anchorage greatly impaired, besides rendering the 
appliance more bulky and less cleanly. 

Sometimes after adjustment of the anchor-band it is found that the 
mesially adjoining tooth inclines buccally to such a degree as to prevent 
the passing of the end of the arch into the sheath. This is readily 
remedied by unsoldering the sheath from the band and resoldering 
it, with a piece of metal of sufficient thickness intervening. Usually 
a portion of a ten-cent piece is ample. By this means the sheath is 
projected buccally sufficient for the ready insertion of the end of the 
arch. 

What has been said regarding the adjustment of the D bands will, of 
course, apply to the adjustment of the X and plain adjustable bands also. 

For directions for cementing clamp-bands see page 783. 

Adjustment of Plain Bands. — Before adjusting, the plain bands must be 
throughly deoxidized by boiling in dilute sulfuric acid. The tooth to 
be banded is then cleansed, dried, and protected from moisture. The 
band is filled with oxyphosphate of zinc of creamy consistence, then 
carried on the end of the finger to the tooth, upon which cement and 
band are pressed. With the fingers alone the band is carefully worked 
nearly to the desired position, and then driven down by a few gentle 
taps from the mallet and band-driver. The burnisher is now quickly 
applied to the edges of the band only, and the surplus cement wiped 
off. When the cement has thoroughly hardened the band should be 
polished and burnished, as it is well known that discoloration is far 
less liable with a smooth, polished surface than with a rough one. 

A band made as described in the section on Soldering, and set as 
above, will fit with the most glove-like accuracy, will present a very 
neat appearance, and will not loosen under necessary strain. If it is 
defective in any particular, as too large, weakened by crimping, or 
slightly torn when driven into position, it should be immediately con- 
demned and a perfect one substituted, for sooner or later it will surely 
fail and cause annoyance. 

In banding a tooth where there is much crowding it may be necessary 
to provide space in advance. Usually, however, by exercising a little 
care and patience the banding may be done at one sitting. 



774 ORTHODONTIA 

Adjustment of Expansion Arches. — In adjusting any of the expansion 
arches, they are first bent to the general form of the dental arch with 
the teeth in their malarrangement. But as the movement of the 
teeth progresses it is occasionally necessary to modify this form, grad- 
ually approaching the ideal, which corresponds w^ith the line of occlusion. 
The expansion arch, therefore, becomes a guide and pattern for the 
proper alignment of the teeth as well as the means of effecting their move- 
ment by reason of its elasticity, in connection with the wire ligatures. 

Being given the desired size and form and being properly adjusted 
to the teeth, its further adjustment as to size is effected by tightening 
the nuts in front of the anchor tubes. The tendency of beginners is to 
depend principally on the tightening of the nuts for applying pressure 
on the moving teeth. This, however, is a mistake, as the principal 
force should be derived from the ligatures and the elasticity of the arch. 

Adjustment of Wire Ligatures. — Unquestionably the greatest modern 
improvement in connection with the use of the arch is the substitution 
of ligatures of brass 1 for fibrous ligatures, on account of their greater 
strength, cleanliness, and freedom from stretching or slipping, making 
their force direct and positive. With them the possibilities in the use of 
the arch are greatly extended, shortening the time of treatment, and 
making easy much that was impracticable or even impossible before. 
One of their valuable qualities is that they may be retightened by twist- 
ing, without renewal, possessing thereby, in addition to their primary 
usefulness, the ideal power of the screw, and obviating the necessity 
for the oft relinquishment and reapplication of pressure on the moving 
tooth, as must follow the use of other ligatures — the principal source of 
pain and inflammation in tooth movement. It is very important, 
however, that only wire of the proper metal, quality, and size be used. 
It is also important that in temper it shall be very soft, so made during 
its manufacture. Wire of spring temper is entirely useless. 

When applying a wire ligature a piece long enough to be firmly 
grasped by both hands should be used, so that strong steady tension 
may be exerted when making the twist. This should never be more 
than three-fourths of a turn at first, as greater twisting gives no addi- 
tional strength, but adds only useless bulk. The surplus ends are then 
clipped off, leaving projections one-eighth of an inch long. These ends 
are then curled under the arch, as correctly shown in Figs. 807 and 811, 
thus providing a smooth surface for the lips. Never attempt to bend 
the twisted portion of the ligature out of the way, as by so doing the 
entire strain is brought on one strand, and the ligature usually broken. 

In retightening the ligature, firmly press the tooth and arch between 
the thumb and finger while giving it another half-turn with suitable 
pliers. Either the large or medium-sized ligatures should be used for 

1 Angle, Regulation and Retention of the Teeth and Fractures of the Maxillae, 
fourth edition. 



ADJUSTMENT AND OPERATION OF APPLIANCES 



775 



the movement of teeth, yet the size of the ligature, the degree of force 
exerted, and the frequency of their renewal or retightening must be left 
wholly to the judgment of the operator. The usual plan is to tighten 
the ligature once or twice a week, although once in two weeks is 
sufficient. 

Although the uses of the wire ligature in orthodontia are limitless, 
there are three principal ways of applying it in ligature form: first, the 
simple ligature, as in A, A, Fig. 807, where it is made to engage a single 
tooth and the expansion arch, where direct labial or buccal movement is 
required; second, where rotation and possibly labial movement is re- 
quired the ligature is made to engage the expansion arch and a spur 
upon a band cemented to the tooth, as in B, Fig. 807; third, the double 
loop ligature, as in C, Fig. 807, to effect the same movement. The 
ligature applied in this manner is more uncertain in its results than 
when applied as last shown, and should rarely be used. 



Fig. 811 




Combination Adjusted. — Fig. 811 shows the expansion arch adjusted 
to the teeth of the upper dental arch in the very complicated case shown 
in Fig. 872. This case required the movement of all the teeth in both 
arches and offered the severest test to a regulating appliance, at the 
same time offering us the best of opportunities for its study, with a 
view to its proper adjustment and operation, not only in this case, but 
for most general uses. Its more extended uses in special cases will be 
noted later in the treatment of individual cases. In this case the upper 
dental arch requires much widening, while both centrals and both 
•laterals are to be carried labially and rotated, and the canines are to 
be elevated in their sockets. 

Plain spurred bands and ligatures were adjusted to all the incisors for 
their combined labial movement and rotation, the spurs on the plain 
bands having been so placed that force exerted by reason of the 



776 



ORTHODONTIA 



elasticity of the arch through the wire ligatures bore most heavily on the 
angles of the teeth that were turned lingually, and as they were rotated 
they were also drawn labially. By using the ribbed expansion arch 
and notching the rib for the more stable attachment of the ligatures, the 
direction of force for moving these teeth was absolutely controlled. 

The first molars, attached to the expansion arch through the clamp- 
bands, were moved buccally by reason of the lateral spring of the expan- 
sion arch. The first premolars were moved in the same direction through 
their attachment to the arch by plain wire ligatures, and the second 
premolars through contact with the screw of the D bands. Pressure 
on the canines to move them lingually was intensified by rubber wedges 
stretched between teeth and arch and the superfluous ends cut off, as 
shown in Fig. 808. 



Fig. 812 




By carefully studying this picture it will be seen how perfectly force 
is distributed to accomplish the various necessary tooth movements, and 
how, as in all fine mechanisms, each part assists and is in harmony with 
each other part. For example, note how perfectly the force is recipro- 
cated from one moving tooth to another; from one lateral half of the 
dental arch to the other, and how this is intensified by the pressure on 
the centre of the expansion arch in front, the tendency being when 
pressure is exerted at this point, as in all arches, to spring the ends 
farther apart. As the central incisors were rotated, much force was 
exerted upon them at their diagonally opposite corners; in reality the 
arch operating on each as two levers combined, the power ends acting 
in different directions. No tooth can resist this force. At the same time- 
all four incisors w T ere carried forward by the irresistible force of what 
is practically two jack-screws combined. 

In the anterior teeth, one lateral incisor reciprocated its force with the 
other, one central with the other, all in perfect harmony. Note, also, what 



ADJUSTMENT AND OPERATION OF APPLIANCES 777 

complete control we have over the teeth singly and collectively, yet at 
the same time the anchorage is derived from practically all of the teeth 
in the arch. m 

In applying force to the moving teeth the medium- sized brass wire 
ligatures were used, being renewed or retightened once or twice a 
week, all the force they would bear being applied to them. The nuts 
of the expansion arches were tightened about one revolution per week, 
always after the ligatures had been tightened. The expansion arch 
was occasionally removed and slightly modified as to form, and the 
full amount of lateral spring maintained. 

With this appliance we may not only expand the arch in all directions, 
as required in this case and here shown, but, as we shall see in the sec- 
tion on Treatment, we may widen or narrow either or both of the dental 
arches on one or both sides, or we may lengthen or shorten one or both 
of the lateral halves. We may move a single tooth in any direction, 
or we may lengthen the teeth, and, to a limited extent, effect their 
shortening. 

In adjusting the arch, as here shown, it will be seen that it is placed 
high up toward the gum, as it should be in all cases. This is necessary 
in order to keep intense, rigid tension upon the moving teeth, for if the 
arch be allowed to slip down (its natural tendency) toward the points 
of the teeth, it will lose much or all of its force, and become a wobbly, 
inefficient incumbrance. For this reason the spurs upon plain bands 
for engaging the ligatures should be placed as high up, or as near the 
gum, as possible, and also, at such an angle as will prevent the ligatures 
from slipping off. 

A common failing of the inexperienced is to give the arch so much 
lateral spring as to cause buccal displacement of the anchor teeth in 
cases in which no buccal movement of these teeth is necessary. 

In using the plain expansion arch, as here shown, spurs are soldered 
at points best calculated to prevent the ligatures from slipping and to 
control the desired direction of force. These spurs are attached with 
soft solder, as previously described (page 764). It is impossible to always 
foretell the exact location at which these spurs should be placed so that 
they may be attached before the arch is adjusted, making the removal 
of ligatures and arch and their readjustment after the spurs have been 
added often necessary. Now, this has a serious objection, for it must 
be remembered , that the relinquishment and reapplication of force to 
moving teeth is the most certain and speedy method of exciting inflam- 
mation, and should be avoided whenever possible. For this reason the 
brass wire ligatures should be retightened without renewal as long as is 
practicable. 

To avoid the necessity of removing the plain arch for the attachment 
of spurs, the ribbed arch was invented, and it is of decided advantage, 
for notches may be made in the rib at desired points quickly and easily 



778 



ORTHODONTIA 



with the arch in position upon the teeth, thus avoiding much pain and 
the liability of exciting inflammation. 

The notches are best made with a delicate knife-edge file, and should 
be made deep enough and at the proper angle to effectually prevent 
the ligatures from slipping. Mere V-shaped notches are useless. They 
should be given decided angles, as shown in the enlarged section, Fig. 
813. The ribbed arch, as here shown, Fig. 813, also gives considerable 
additional force in widening the dental arch, so that reinforcement by 
means of the lingual wire (Fig. 811) is now rarely necessary. 

Fig. 813 




Objections have been offered to the ribbed arch on account of its 
supposed greater liability to abrade the mucous membrane of the lips, 
but the writer has always found that the arch was not properly adjusted 
when this occurred, but had been allowed to stand out from the teeth, 
sometimes to an absurd degree, instead of conforming compactly to the 
teeth, as shown in Fig. 769. Again, the superfluous ends of the rib should 



Fig. 814 




E.H 



be removed with a file and the arch neatly burnished, especially if, 
through necessity, the arch is given much prominence on account of 
the position of the canine teeth. When intelligently studied and properly 
managed the great value of the ribbed arch will become better and 
better appreciated. 

Fig. 814 shows the adjustment of the combination to the lower dental 
arch. It will be noted that the principal necessary movement of the 



ADJUSTMENT AND OPERATION OF APPLIANCES 779 

canines is buccally, so the notches in the arch have been placed well 
back to best accomplish this movement. Later it may be necessary to 
place bands and spurs on the right canine and on the central incisors in 
order to better control their movement for partial rotation. 

By the addition to this combination of sheath-hooks and rubber liga- 
tures used in the Baker anchorage, all of the upper teeth may be moved 
distally and all the lower teeth mesially, as illustrated in Fig. 706, or 
these movements may be reversed, as shown in Fig. 812, and all this in 
connection with any other tooth movements that may be required in 
either or both arches. 

The modifications of form and directions of spring, plus the modifi- 
cations in ligature attachments, make it possible to derive wonderful 
control of force in tooth movement, and in the use of this appliance it 
is possible to cultivate a very high degree of skill. It typifies efficiency 
and simplicity. It is easily applied, and is so stable in its attachment that 
there need be no slipping or loss of power. It is cleanly, and occupies a 
position in the mouth that causes the least inconvenience to the patient. 
If this device be intelligently managed, it need interfere but little with the 
normal functions of the mouth. On the contrary, however, if improperly 
managed it becomes a constant annoyance, as has been said, and one of 
the most wobbly and useless of devices. 

In its proper use the widest range for reciprocal anchorage is possible. 
We may also gain simple and a considerable degree of stationary anchor- 
age by reason of the tubes and firm attachment of the anchor-bands to 
the teeth used as anchorage, and also, as we have seen, the very valuable 
intermaxillary anchorage. 

The necessary direction and distribution of force should be carefully 
studied in each case, as well as the effect upon the anchor teeth and all 
teeth that are in correct position. 

Let us repeat that the arch should always be made to lie approxi- 
mately close to the teeth, so as to interfere as little as possible with the 
functions of the lips. 

It should be remembered that as its force in tooth movement is exerted 
usually by its elasticity, its careful bending in order to secure the proper 
degree and direction of force is of much importance. To make the 
most of this possibility, and at the same time avoid interference with 
desired movements or with teeth already in correct position by binding, 
is the most difficult problem in its management, and yet it is easily solved 
if intelligently studied in each case. 

As a result of years of experimenting, it is believed that, as here shown, 
with its improvements and attachments (Fig. 760), it is very nearly 
perfect. 

In order that the patient may become gradually accustomed to the 
appliances, the bands should be worn for two or three days, then the arch 
added without ligatures for three or four days more, and finally, all care- 



780 ORTHODONTIA 

fully and thoroughly adjusted and the ligatures applied for the movement 
of the teeth. They should be very light of tension at first, the object 
being, of course, to begin so gently that the patient may become accus- 
tomed to the wearing of the device with no pain and with but the mini- 
mum amount of inconvenience, all of which is easily possible. The 
tendency of all appliances upon the teeth is at first to excite more or 
less inflammation, which will be in proportion to the amount of force 
exerted; therefore we cannot too strongly recommend that the adjustment 
of the appliances should always be gradual, and the force exerted in the 
beginning most gentle. Later, much pressure can be borne with little 
inconvenience. 

Although in cases met with for treatment the malocclusion always 
differs, the adjustment of the expansion arch as here given is practically 
always the same, the principal difference being in the form given the arch 
by bending in order to exert force in the desired direction, and in the 
direction of the ligatures and their attachments to the teeth to be 
moved. 

Combinations for Intermaxillary Anchorage. — Fig. 806 shows a very 
important combination of the expansion arches in which the inter- 
maxillary anchorage is used in the movement distally of the teeth of 
the upper and mesially those of the lower arch in the correction of the 
malocclusion of cases belonging to Class II. 

The expansion arches are adjusted in the usual way, sheath-hooks 
having been attached to the upper at points opposite the lateral incisors. 
Either the plain or ribbed arches may be used, but the plain arch is 
preferable in this combination unless other movements of the incisors 
and canines are necessary, as already described, and illustrated in Fig. 
811. The force is exerted by means of one or more small rubber liga- 
tures on each side, which engage the sheath-hooks on the upper expan- 
sion arch and the distal ends of the sheaths of the anchor-bands on the 
lower molars. For description of the operation of this combination of 
appliances in treatment, see page 851. 

The combination of appliances for the treatment of cases belonging 
to the subdivisions of this class is identical with that just described, 
except that intermaxillary force is limited to the side of the arches in 
distal occlusion. Only one sheath-hook should be used, with its accom- 
panying rubber ligatures. 

In the treatment of cases belonging to Class III the same combina- 
tion of appliances is used, but the plan of operation is reversed, as 
shown in the diagram (Fig. 812). The sheath-hooks are attached to the 
lower expansion arch, well forward, and rubber ligatures are stretched 
between them and the distal ends of the sheaths of the anchor-bands on 
the upper molars. 

For the treatment of cases belonging to the subdivision of Class III 
the same combination of appliances is used, with force from the rubber 
ligatures exerted on the abnormal side only. 



ADJUSTMENT AND OPERATION OF APPLIANCES 781 

It will be seen that all cases of all classes may be treated with this 
appliance, and, we now believe, more quickly, more easily, far better, 
and with far less inconvenience to the patient than with any other form 
of appliance. It is the one that seems to be most natural to meet the 
demands of occlusion, for with it we can have control of the entire 
dental apparatus — something impossible in the use of the innumerable 
appliances that have been devised for the correction of symptoms only, 
without regard for the laws of occlusion. He who will study its possi- 
bilities will be more and more impressed with its wonderful efficiency 
and great simplicity. 

Expansion Arch Reinforced. — The elasticity of the plain expansion 
arch is sufficient to exert ample force for widening either of the dental 
arches; yet in very rare instances where the patient has reached maturity, 
the force may not be sufficient to accomplish the desired movements as 
rapidly as may be wished. To meet this limitation the arch may be 
reinforced by a piece of spring wire, which should be adjusted to exert 

Fig. 815 




pressure upon the lingual surfaces of the anchor-bands, as in Figs. 811 
and 815, and attached on each side by uniting two short tubes, R and D, 
at right angles, the longer one slipped over the end of the screw of the 
D band, and the ends of the lever bent sharply at right angles and made 
to engage the short tubes. Any desired degree of force may be easily 
gained with this simple method of reinforcement. 

A simpler way of securing the reinforcement spring is to insert its 
finely pointed ends, bent sharply outward at right angles, into very 
delicate perforations made in the anchor-bands at their mesio-lingual 
angles, as in Fig. 878, the ends passing through the band and extending 
between enamel and band. 

In Fig. 815 the threaded ends of the arch are seen to project through 
the distal ends of the sheath. This is never permissible. The ends of 
the arch should be clipped off even with the ends of the sheaths and the 
roughened ends made smooth, otherwise painful abrasions of the cheeks 
are likely to follow. 



782 



ORTHODONTIA 



MISCELLANEOUS COMBINATIONS 

Traction-screw. — Although there are many possible combinations 
with the traction-screw, in reality its uses should be limited to two or 
possibly three. Formerly its most important use was that of retraction 
of that most obstinate tooth, the canine, as shown in Figs. 816 and 
817. This it accomplishes so easily and so perfectly, when properly 
adjusted and managed, that it easily takes rank, we believe, over all 
other appliances for this purpose; but since the advent of intermaxillary 
anchorage, making extraction in treatment unnecessary, its use is 
rarely required. 

In its correct adjustment the canine and the anchor tooth are carefully 
banded after the manner described for adjustment of the plain and 
anchor-bands. The traction-screw is then held in position, and the 
short and long sheaths made to touch the bands at the exact points they 
are to occupy when soldered. With a suitable instrument the anchor- 




Fig. 817 



E.H.A 




band is scratched parallel with the long sheath to indicate its align- 
ment. The side of the long sheath is then filed to permit of close con- 
tact with the band and to give increased surface for the solder, filing 
through being carefully avoided. The band is then replaced, and the 
exact point of contact of the edge of the short sheath with the band 
on the canine is located and indicated by a suitable mark. Lest this be 
obliterated upon soldering, the band may be perforated at this point 
with a small drill. Having noted as accurately as possible the angle at 
which this sheath shall stand to properly line with the right angle of 
the shaft, minute notches are made in the edge of the band mesially and 
distally, to line with the end of the sheath (Fig. 818). The bands are 
now removed from the teeth and the sheaths from the screw, and a 
minute piece of solder partially fused upon the edge of the short sheath 
at the point intended for attachment to the band. It is then held with 
pliers in the left hand, the band being held by its untrimmed ends in 
the right hand, the end of the sheath lining with the notches A and B, 
Fig. 818, and the solder fused by contact with the flame at the proper 
point. 



MISCELLANEOUS COMBINATIONS 783 

It is highly essential that the sheath be attached at the right point 
and at the proper angle, or the angle of the screw will not fit. 

Be it remembered that the sheath attached to the canine band must 
always stand at right angles to the long axis of the tooth, that a free 
hinge-like movement of the tooth in retraction may be gained; not 
parallel with the long axis, as some will persist in attaching it, with 
resultant binding and prevention of free movement. 

The surplus ends of the band are now trimmed off and smoothed, 
and the band deoxidized and cemented in position. While the cement 
is hardening the long sheath is soldered, according to alignment, to the 
No. 2 band. It is then cleansed and slipped upon the screw and the 
nut adjusted, the angle is hooked into the sheath upon the canine band, 
and the clamp-band slipped over the crown of the molar and gently 
tightened. It is allowed to remain a day or two before cementing, in 



Fig. 818 




order that this operation, so important to thoroughly perform, may be 
accomplished without interference by pressure from the approximal 
teeth, and also that both the canine and the anchor tooth mav sli^htlv 
move and become more perfectly adjusted to their relations with the 
two bands. 

The proper length of the screw having been determined, it is cut 
off behind the nut. Heat must in no instance come in contact with 
any portion of the shaft of the screw. 

Before finally cementing the molar band in position it should be 
removed, and it and the crown of the molar thoroughly cleansed and 
dried. The crown being properly protected from moisture, cement is 
mixed to the correct consistence and the interior of the band nearlv 
filled. The angle of the traction-screw is then inserted into the short 
sheath, and the anchor-band and cement carried down over the crown 



784 



ORTHODONTIA 



of the molar with the thumb and finger, forcing the cement well down 
by pressure from the thumb. The band is quickly worked to the desired 
position, and the nut of the band tightened until it is firmly clamped. 
The superfluous cement is then wiped off, and the patient dismissed 
until the next sitting before tightening of the nut of the traction-screw 
is begun, in order that the cement shall become thoroughly set and 
the most rigid possible attachment gained. 

If the operation thus far has been carefully performed, the nearest 
approach to stationary anchorage possible to obtain in the mouth will 
have been gained, so that the canine may be moved distally without 
changing the relation of the occlusal planes of the anchor tooth with 
those of the opposite jaw. It is very important, however, not to strain 
the attachment by overtightening the nut of the traction-screw at any 
time. One-half a revolution the nut each day or just enough to exert 
a slightly snug feeling upon the canine, is all the force that should be 
exerted at any one time. 



Fig. 819 



Fig. 820 




*W& 



E.H.A 




E.H.A. 



It is very important that the angle of the screw be passed into the 
sheath its full length, otherwise it will be broken when force is exerted. 

If it is desired to rotate the canine as it is moved distally, it may be 
accomplished by using a staple instead of a sheath for engaging the 
angle of the traction-screw, as shown in Fig. 819. In this instance the 
angle of the screw is parallel with the long axis of the tooth, instead 
of at right angles to it, as when the tube is used. In this manner force 
is exerted on one side of the band only, and rotation as well as retrac- 
tion takes place. 

The shifting of the canine lingually or labially in its distal move- 
ment may be accomplished by bending the screw where it enters the 
sheath. As the nut is tightened the screw is gradually straightened as 
it is drawn into the sheath, thus arranging the teeth in proper align- 
ment. 



MISCELLANEOUS COMBINATIONS 785 

Fig. 819 shows the use of a traction-screw in effecting rotation of a 
premolar tooth in combination with the clamp-bands Nos. 1 and 2. 
The angle of the screw engages a staple made of the G wire soldered 
to the mesio-lingual angle of the band encircling the premolar. By 
tightening the nut at A, traction force is exerted on one side only, while 
resistance in the opposite direction is offered by the intervening pre- 
molar. The great power thus exerted makes this the most efficient 
method known of rotating a premolar, and is one that is occasionally 
used by the writer, always with much satisfaction, but only used when 
a single tooth is greatly turned upon its axis, as in cases belonging to 
the first division of Class II, where, after all the other teeth have been 
moved into their normal relations, it is desirable to remove the expan- 
sion arch and effect retention, when rotation of this tooth may be fin- 
ished, as here described. In such cases the expansion arch may be 
used at the same time, in combination with this appliance, in which 
case the clamp-band D would be adjusted to the second molar. Of 
course, all ordinary rotation of premolars would be effected in the usual 
way, or by means of plain spurred bands, wire ligatures, etc., in com- 
bination with the expansion arch. 

In Fig. 820 is shown another use of the traction-screw in effecting 
the labial movement of a lateral, and at the same time providing space 
for its movement. A strip of band material F is looped around the 
lateral, the ends resting on the labial surfaces of the adjoining teeth. 
To one end is soldered vertically one of the short tubes D, while on the 
other end is a similar tube attached horizontally. Into these tubes the 
traction-screw is placed, being bent to conform to the proper curve of 
the arch, and as the nut is tightened the ends of the ribbon of band 
material are pushed farther apart, thus providing space for the lateral 
as it is carried into correct position. This combination is now practically 
obsolete for the movement of the lateral, as here described, or for any 
of the anterior teeth, the same movements being far more easily accom- 
plished by means of the expansion arch. Yet it is valuable on rare 
occasions for moving buccally a premolar that is in marked lingual 
occlusion, as in Fig. 828, as it effectually provides space for the tooth 
while moving it buccally. When so used the screw is left straight, lying 
close against the buccal surfaces of the teeth. 

Fig. 821 shows a combination of traction-screw and expansion arch 
for shortening one of the lateral halves of the dental arch, and at the 
same time correcting malpositions of the incisors. 

The traction-screw should be first adjusted, as already described, and 
in addition it should be provided with one of the tubes D soldered to 
the side of the sheath Y, near its mesial end. This is for the reception 
and support of one end of the expansion arch in place of the usual D 
or X band. The nut of the expansion arch is to bear against this tube, 
and when so used the nut should be reversed, the extension flange turned 
50 



786 



ORTHODONTIA 



mesially. The other end of the expansion arch is supported in the usual 
way, as in Fig. 808. As the canine is retracted into the space made 
vacant by the loss of the first premolar, the malposed incisors are rotated 
by means of the ligatures, bands, and spurs, as is well shown in the 



Fig. 821 




engraving, and also in Fig. 811. This very efficient combination was 
formerly a great favorite with the writer, but it is now rarely employed, 
as intermaxillary anchorage has made the establishment of normal 
occlusion in such cases easily possible and the sacrifice of the premolar 
unnecessary. 



Fig. 822 



Fig. 823 




NO. 2 




E.H.A. 



Jackscrew. — Since the Dwindle jackscrew was introduced in 1848 
for orthodontic purposes, it has been much employed by dentists. 
The writer's jackscrew was formerly a very important part in many of 
the combinations of his appliances, and notwithstanding that he believes 
he is the author of by far the most perfect form of jackscrew yet given 
to the profession, and one that is widely used and often imitated, he 
believes that in the requirements of modern orthodontia it is one of the 



MISCELLANEOUS COMBINATIONS 787 

poorest of appliances and that its use should be practically discontinued, 
it having been superseded by the expansion arch, for practically all of the 
movements possible to accomplish with the jackscrew are better and 
more easily performed with the expansion arch. With the latter we 
may have complete control of the force exerted on both anchor and 
moving teeth, individually and collectively, at the same time guarding 
the positions of those teeth already in the line of occlusion, while with 
the jackscrew our control over the force is necessarily greatly limited. 
Yet in favorable cases, which are rare, it will doubtless always be a 
desirable method of exerting force, owing to its great simplicity and 
power. Fig. 822 shows one of the writer's favorite methods of using 
the jackscrew. 

An anchor band provided with a spur of wire, G, engages one end 
of the jackscrew. The flattened end is notched and engages a staple 
soldered to the lingual surface of a band on the tooth to be moved. 
The jackscrew is powerfully reinforced by a section of the wire G, as 
illustrated. This wire engages one of the tubes, R, soldered at right 
angles to the sheath near its base, its ends being bent in the form 
of hooks which engage wire ligatures encircling the canine and central 
incisor. 

Lever. — The spring lever, L, also formerly played an important part 
in the combinations of the writer's appliances for accomplishing rota- 
tion of the teeth, but with it, as with tiie jackscrew, it is difficult to 
control the distribution of force, so it, also, has been largely superseded 
by the expansion arch. 

In some instances, however, it is valuable; for example, after teeth 
have been rotated and have, through accident, partially relapsed, 
they may be easily readjusted, as it requires but little force, by means 
of a band provided with a tube, R, for the insertion of the power end 
of the lever, the long end being sprung around and attached to a favor- 
ably located anchor tooth which may be reinforced, as shown in Fig. 
823. Or the attachment to the anchor teeth may be effected by wire 
ligatures. 

Double rotation, as shown in Figs. 824, 825, and 826, may also be 
accomplished by means of the lever made to exert force by engaging 
tubes, or spurs and ligatures, as shown in the engravings; but we insist 
that they should rarely be employed in the first adjustment of the teeth, 
as teeth in these positions are usually only the prominent symptoms 
of more or less general malocclusion which demands attention first. 
For this reason the expansion arch, acting upon all of the teeth, thus 
providing space for the moving teeth, as well as effecting their movement, 
is best. But, as we have said, for teeth that have partially relapsed these 
are simple and efficient ways of readjusting them, as well as for their 
temporary retention. 

A novel way of effecting double rotation and retention in simple 



788 



ORTHODONTIA 



cases is shown in Fig. 827. Spurs or tubes soldered to the mesio-labial 
angles of bands on the central incisors are engaged by a wire ligature, 
which, being tightened, draws the teeth mesially, while force in the 
opposite direction is exerted by a rubber wedge stretched between 
these teeth and resting in contact with their mesio-lingual angles. 



ii 



Fig. 824 



Fig. 825 






■HI 



Fig. 826 




Another simple but often useful little appliance is shown in Fig. 
828, where a tooth is being moved into the line of occlusion by means of 
either a rubber or wire ligature made to engage the tooth to be moved 
and a section of wire G, which is held in position by attachment, either 
by solder or a tube, to a clamp band encircling an adjoining tooth. 



Fig. 827 



Fig. 828 





Fig. 829 shows the simplest of all regulating devices, yet one that is 
very efficient and valuable, especially in increasing the distance between 
deciduous canines, as here shown, to release lateral pressure upon 
erupting permanent incisors. 



Fig. 829 




z*A. 



It consists of a section of wire G, the ends sharpened and made to 
rest in delicate pits in the enamel of lower deciduous canines. Irresistible 
force is brought to bear on these teeth by an occasional pinch of this 



RETENTION 



789 



wire with the regulating pliers, the effect being to lengthen the wire. 
The lower teeth so moved will act through their inclined planes upon 
the upper canines, and in like manner effect their buccal movement, 
thereby releasing pressure from the upper permanent incisors. This 
would be the ideal treatment for such cases as that shown in Fig. 712. 



Fig 



Fig. 831 




As here described, it is useful, of course, only on young patients, with 
the wire pinched only at long intervals, say a month intervening. The 
same principle, however, is often made use of by the writer in older 
patients. In these cases a thoroughly annealed section of one of the 
expansion arches is used, its end secured by solder to bands cemented 
upon the canine teeth, as shown in Figs. 830 and 831. 



RETENTION 



After malposed teeth have been moved into the desired positions, it 
is of the greatest importance that they be mechanically supported until 
all tendency to return to their former malpositions has subsided; but it 
cannot be too strongly insisted upon that unless such occlusion has been 
established as will enable the inclined planes of the cusps to ultimately 
act in harmony for mutual support, permanency of the teeth in their 
new positions after the retaining devices have been removed cannot be 
hoped for. It should be borne in mind that all retaining devices are 
only temporary assistants to the permanent establishment of the normal 
functions of the occlusal planes of the teeth, and of harmony in the forces 
which act upon the teeth. 

Time Required for Retention. — The time required for mechanical 
retention varies, according to the age of the patient, occlusion, tooth 
movements accomplished, length of cusps, health of tissues, etc., from a 
few days to a year or two years, or even longer, while perhaps in rare 
instances retention may be required for an indefinite period. 

The support of teeth that have been directed into correct positions 
during the period of eruption is usually required for a few months only, 



790 ORTHODONTIA 

while a much longer period (at least a year) would be required for the 
same teeth if moved after the full development of their alveoli. 

Again, owing to the great disturbance of the fibers of the peridental 
membrane of a tooth which has been rotated, its retention requires a 
far longer time than if the movements labially or lingually had been 
accomplished. 

A rule of general application may be made, that three times the 
length of time will be required for retention of teeth of patients aged 
twenty-one years as for those of patients aged twelve, the same tooth 
movements having been performed. 

There is usually a temptation to remove the appliances before the 
teeth have become thoroughly established, and many are the failures 
from this cause of otherwise well-conducted cases. As so much depends 
upon this part of the operation, it is far better that the appliances be 
worn even longer than necessary, than that they be too early removed. 

Principles of Retention.— As the tendency of teeth that have been 
moved into occlusion is to return to their former malpositions, the main 
principle to be considered by the designer of a retaining device is the 
antagonizing of the teeth in the directions of their tendencies only. 
Very slight antagonism is required, but its exercise must be constant. 
If the student will keep this fact in view he will realize that only delicate 
devices are necessary, and will be impressed with the utter uselessness 
of much of the bulk and material composing so many of the retaining 
devices shown in our literature. 

With this in view, each corrected case should be carefully studied 
in connection with the original models, noting the various directions in 
which the teeth are inclined to move. 

To secure retention we have at our disposal support or anchorage 
from the following sources: first, reciprocal, or the pitting of one tooth 
against another, their tendencies being to move in opposite or different 
directions; second, teeth already firm in the arch; and third, and ulti- 
mately most important, the occlusion of the teeth. 

As the retaining device is to be worn for a considerable time, some 
prefer its construction from gold instead of nickel silver, on account of 
the tendency of the latter to discolor in some mouths; but it is a fact, 
which anyone may verify by experiment, that bands of the same deli- 
cacy will give far less trouble by loosening if made of nickel silver than 
if made of gold or silver, or of any other of the alloys, and hence are 
preferable, at least during the experimental period of retention. 

The appliances necessary for retaining the teeth need never be bulky 
nor complicated, nor comprise a large number of pieces. We must 
remember that the patient is probably already wearied with the incon- 
venience of the regulating appliances, so it should be the aim to make 
the retaining devices as delicate, compact, and inconspicuous as possible, 
always, however, consistent with the main object — perfect support. 



RETENTION 791 

The more securely the teeth are held, the more rapidly will they become 
firm in their new positions. For this reason, and that they may be as 
little as possible under the control of the patient, the appliances should 
be made stationary by the attachment of accurately fitted and cemented 
bands whenever practicable. They should also be readily cleansible 
by the patient with the brush, that they may in no way injure the teeth, 
no matter how long worn. It is remarkable how compact, simple, 
efficient, and cleanly the retaining devices may be made, even for the 
most complicated conditions. 

The problems to be met in retention are limitless in their variation, 
and often difficult, and the possibilities for the development of skill 
are also limitless. We will here suggest only such devices as embody 
principles which admit of great variation and which have been most 
satisfactory in the writer's hands. 

Retention of Teeth in Cases Belonging to Class I. — As the movement 
of teeth in cases belonging to Class I has been conducted independent 
of the mesial or distal positions of the teeth of the opposing arch, a con- 
dition met with in cases belonging to Classes II and III, we have here but 
to consider methods of resisting the movements of individual teeth in 
each arch, independent of the teeth in the other arch, and usually teeth 
anterior to the molars only. 

Temporary Retaining Devices. — before adjusting the retaining device, 
it is often best to allow the regulating appliances to remain passively 
in position upon the teeth for two or three weeks, in order that all ten- 
derness of the teeth may subside. Yet upon the removal of the regulating 
appliances there is usually found to be more or less soreness, as well as 
mobility, in the teeth. It is, therefore, difficult or impossible to form and 
fit bands with any considerable degree of accuracy without occasioning 
pain, and pain may and should be avoided. After removing the 
expansion arch and thoroughly cleansing the teeth, it is best to adjust 
a temporary device, often with the same form as if it were to be per- 
manent, with looser fit of bands, which may be gently worked into 
position with the fingers alone. If a good quality of cement be used 
the device will be firmly held in position for a few weeks, until all sore- 
ness shall have subsided, when a device, with bands and all other parts 
of the most perfect fit and finish, may be substituted. This may be of 
precious metal if desired. 

Another satisfactory plan for temporary retention is to weave strands 
of the wire ligatures about the teeth, engaging the spurs upon the bands 
which have been used in effecting the various tooth movements, and 
in this way antagonizing the teeth in the direction of their tendencies. 

This is an excellent method of temporary retention, and one that may 
often be taken advantage of, as was done in the case shown in Figs. 
832, 833, and 834. A wire ligature was made to engage the spurs on the 
central incisors, both ends brought forward and tightly twisted at the 



792 



ORTHODONTIA 



mesio-labial angles of the centrals. Then another ligature was made 
to engage the spur on the disto-lingual angle of the left lateral incisor, 
the ends brought forward across its labial surface, one end being passed 
between the central and lateral and made to engage the spur upon the 
left central, brought back between these teeth, and firmly twisted with 
the other end of the strand of ligature at a point on the labial surface of 
the lateral incisor, as indicated. In precisely the same manner a third 
ligature was made to engage the spurs upon the right lateral and central, 
all as shown in Fig. 833. By studying the original positions of the teeth 
in Fig. 832, it will be seen how direct and positive is the reciprocal force 
exerted by these ligatures in resisting the movement of the teeth in the 
direction of their tendencies. 



Fig. 832 



Fig. 833 



Fig. 834 






After a few weeks of temporary retention the teeth were permanently 
retained, as shown in Fig. 834, by other bands placed upon the laterals 
and connected by a section of wire in the usual way, as described else- 
where. 

Permanent Retaining Devices. — The simple band and the short pro- 
jecting wire, which for convenience we call a spur, form the basis of a 
principle which is applicable to nearly all the requirements of per- 
manent retention in all the various classes. It is surprising to find in 
what number of combinations the band and 
spur may be employed. If a single tooth has 
been rotated, it may be prevented from return- 
ing to its former position (or antagonized in 
the direction of its tendency) by a band with 
two spurs, as in Fig. 835. These may be 
soldered directly to the band. Unnecessarily 
long spurs should never be used, as they are 
cumbersome and unsightly. Even shorter spurs than those shown in 
the engraving may be employed. 

Much care should be exercised in placing the points of the spurs 
which bear against the adjoining teeth so that they will not cause dis- 
placement of the tooth retained. If placed as shown in the engraving, 
the elevation of the lateral in its socket would be inevitable, on account 
of the inclined planes of the adjoining teeth down which the spur will 
be made to slide by the tooth in its tendency to return to its original 
position. (This point may be taken advantage of, however, in some 
cases in which it is desirable to force the eruption of a tooth slightly; for 




RETENTION 



793 



example, a canine.) The point of the spur in the case shown should 
bear upon the gingival ridge of the central, while the point of bearing 
upon the canine should be above the swell of the crown. The fine 
adjustment of the spurs should be left until the cement has hardened 
after setting the band, when they may be bent until their ends touch at 
the exact points required. In some instances in which the period of re- 
tention is to be protracted, or where bands would be unpleasantly 
conspicuous, spurs may be set in fillings, as in Fig. 836. In the case of 
deciduous teeth soon to be lost, spurs may be cemented in cavities 
drilled in the enamel for the purpose, in preference to the setting of 
bands. 

A method often desirable when the space of a lost tooth is to be pre- 
served is to insert between two bands on the approximating teeth a short 
section of wire, G, its ends being engaged in tubes R soldered to the 
bands, as in Fig. 837. This wire may be lengthened, if it is desired to 
increase the space, by pinching it with the regulating pliers. 



Fig. 836 



Fig. S37 





E.H.A. 



Fig. 838 



Another excellent modification of this plan is shown in Fig. 838, in 
which one band is dispensed with, one end of the section wire G being 
bent in the form of a goose-neck to engage the mesial surface and sulcus 
of the first premolar, the other end being soldered directlv to a plain 
band on the lateral incisor. If two approximating teeth have been 
rotated in opposite directions, the firmest 
support is given them by encircling each 
tooth with a band, across the labial surface 
of which a section of wire is soldered — prac- 
tically two bands and spurs united. The 
spring of the spur makes possible a greater 
precision in the adjustment of the bands, 
with less liability of subsequent loosening, 
than when the bands are united directly 
by solder. 

The tendency to rotation of the right 
central and lateral incisors, plus the lingual 
tendency of the left central and the mesial 
tendency of all, is effectually resisted by two 

bands connected by a spur, with an additional spur made to bear upon 
the mesio-labial angle of the right lateral, as in Fig. 839. The engraving 
shows the ends of the wire G, secured by engaging tubes soldered to the 




E.H.A. 



794 



ORTHODONTIA 



lingual surfaces of the bands. Direct attachment of the ends of the 
wire to the bands by solder may, of course, also be used, and is prefer- 
able. By studying the tendency of the teeth, it will be seen how effect- 
ually they are resisted by this device. 



Fig. 839 



Fig. 840 



Fig. 841 






EH A. 



E.H A. 



E. H. A 



Fig. 840 shows the union of two bands by a section of wire G, em- 
ployed to antagonize the lingual tendency of two lateral incisors which 
have been moved labially into the line of occlusion, while another com- 



Fig. 842 




E. H. A 



bination of bands and spurs (Fig. 841) attached to the centrals would 
accomplish the same result. The former device is more efficient, but 
less esthetic than the latter. 



Fig. 843 




Fig. 842 shows a combination of bands and spurs of great simplicity 
used to resist the tendency of the incisors to return to their original 
positions, which are shown in Fig. 843. 

Neatly fitting bands upon the central incisors are connected on their 



RETENTION 



795 



lingual surfaces by a section of the wire G, the ends of which project and 
bear against the disto-lingual surfaces of the laterals, while two spurs 
are soldered to the disto-labial angles of the bands on the central incisors 
and bear against the mesio-labial angles of the laterals. This is probably 
the simplest possible device for resisting these movements. It is impor- 



Fig. 844 



Fig. 845 




■ 




tant that it be adjusted with accuracy, and also that the ends of the wire 
be carefully placed, for reasons given in connection with the description 
of Fig. 835. In some instances it may be an advantage to provide a 
suitable resting place for the lingual spurs by slightly grooving the 
marginal ridge of the laterals. 

Dr. Jane Bunker has ingeniously modified this device, as shown in Figs. 
844 and 845, in which a section of wire is soldered across the labial sur- 



Fig. 846 



Fig. 849 




Fig. 847 




Fig. 848 





E.H.A. 



Fig. 850 




faces of the two bands on the centrals, after which all of that portion 
of the labial surface of the bands above and below the spur is carefully 
cut away, so that the wire only is in evidence. 

Two lingual spurs engage the laterals. 

This plan of removal of a portion of the band may be variously 



796 



ORTHODONTIA 



applied, and where efficiency is in a degree sacrificed for esthetics, the 
device will be found sufficiently firm as to make its use often desirable. 
It should be remembered that its weakest point is where the band 
emerges between the teeth to join the wire. It should be properly 
strengthened at this point with solder. 

Another very useful plan for accomplishing the same result is to 
solder a section of wire G, directly to the labial surface of a band on 
each lateral, the ends being made to rest against the labial surfaces of 
canines and centrals. 

Fig. 851 




Fig. 846 shows the union of two bands by a section of wire G, which 
would not only accomplish the same result, but would also resist lateral 
pressure or rotation of one or both of the canines if required, while an 
additional spur, as in Fig. 848, would antagonize the tendency of the 
central shown in Fig. 847. 

By the addition of two spurs to this combination, as in Fig. 850, 
the lingual and buccal tendencies of the first premolars are also resisted 
in the more complicated case shown in Fig. 849. 

Another very simple but very efficient plan of retention is shown 
in Fig. 851. Bands are placed on the lateral incisors, each pro- 
vided with a short spur which engages the disto-lingual angle of the 
centrals, and two long spurs, soldered at the disto-labial angles of 



RETENTION 



797 



the lateral bands, bear heavily upon the canines as they pass distally 
to be engaged by wire ligatures encircling the premolars. Thus, the 
proper width of the arch, as well as the positions of the incisors and 
canines, are maintained. This is a favorite device with the writer, and 
is susceptible of many variations. 

It will be seen that any or all of the incisors and canines may be 
firmly supported by combinations of the band and spur, and that the 
premolars and molars may be included by extending the principle, but 

Fig. 852 






E. H. A. 



its greatest usefulness is limited to the incisors and canines, or at most 
extended to include the first premolars. If, however, a single premolar 
shall have been rotated, or if a single molar or premolar shall have been 
moved lingually or bucally, the band and double spur made to bear 
against the adjoining teeth, the same as already described for retention 
of an incisor, will be most efficient. 

In the use of all bands in retention we would caution that they be 
inspected at least once in two months, for if they should become loosened 
they would act as receptacles for food particles, the fermentation of 
which might in time injure the enamel. 

A very simple and efficient retaining device for upper molars that 
have been moved from lingual occlusion, and for lower molars that have 
been moved from buccal occlusion, as in Figs. 872 and 877, is a band 
and spur placed upon the upper molar, the spur or finger being made to 

Fig. 853 





E.H.A. 



bear against the incline of the buccal surface of the lower molar, or the 
mesial or distal angle of a lower molar or premolar, shown in Fig. 852. 
Not only is this device efficient as a retainer, but it is also valuable as 
a regulating device, for by occasionally bending the spur to increase its 
efficiency, the buccal movement of the upper molar and the lingual 
movement of the lower may be accomplished to any desired distance, 
or they may to some extent be shifted mesially and distally by so placing 
the spurs as to exert a mesial or distal influence. 
The spur may also with advantage be made in the form of a staple 



798 



ORTHODONTIA 



in some instances, as in B, Fig. 853, as its double attachment to the 
band insures greater strength. 

The union of band and spur should be reinforced with plenty of solder 
and only the best quality of band and cement used. 

When a number of the molars have been moved buccally, a metal or 
vulcanite plate for their retention, as illustrated in Fig. 854, has long 
been a favorite with many. Its greatest objection, as with all removable 
retainers, is the uncertainty of its being worn by the patient. The 
lingual arch, for the same purpose, is preferred by many. It should 
be elastic, and to avoid injury by heating should be made of iridio- 
platinum or some of the combinations of precious metals. 



Fig. 854 




There are many ways of attaching it, two of which are shown in 
Figs. 855 and 856. 

Still another manner of using the lingual arch, which, especially 
during the latter stages of retention, has become a favorite with the 
writer, is shown in Fig. 857. It is made in three sections and soldered 
to the ends of screws of clamp-bands which latter are afterward cemented 



Fig. 855 



Fig. 856 





and clamped upon the molars. Delicate spurs of soft wire may be 
soldered to the lingual wire, then passed through the interproximal 
spaces between the incisors and bent to bear against the angles of these 
teeth to prevent their rotation, and then clipped off. Or, the incisors 
may be supported by bands, spurs, and ligatures which engage them 
with the lingual segment of the arch. 



RETENTION 799 

In the very great tissue changes that have taken place in all such 
cases as the one described on page 732 (Huning), it must be apparent 
that there is a vast amount of tearing down of bone by the osteoclasts, 
and its rebuilding by osteoblasts, as well as similar cellular and structural 
changes of the other tissues involved. Very naturally, and a fact proved 
by experience, these changes are most active and the growth of bone 

Fig. 857 




most pronounced in cases treated during the active period of growth 
and development of the dental apparatus, this activity naturally dim- 
inishing with the advancing age of the patient, necessitating longer 
periods of retention as the patient nears maturity, and after maturity 
the development is very slow and probably never complete. 

With a view to expediting the treatment of malocclusion, by short- 
ening the period of retention in these cases, the writer has devised a 



800 



ORTHODONTIA 



method of retention by which he believes the cells involved in these 
tissue changes will be gently stimulated to greater activity, with the 
more speedy and complete development of the tissues. 



Fig. 858 




The device is shown in Figs. 858 and 859, and is for the purpose not only 
of supporting the crowns of the teeth in their corrected relations with 
the line of occlusion, but also to exert a very gentle but constant force 



Fig. 859 




labially upon the roots of the incisors. It may be regarded as a 

"working retainer," as appropriately named by Dr. George B. Palmer. 

The device is made by removing the segment between the threaded 

ends of the expansion arch that was employed in accomplishing the 



RETENTION 801 

movements of the teeth, and substituting for it a segment, of the same 
length and curve, of very delicate and elastic wire of precious metal 
attaching the ends of this wire to the threaded ends of the original 
arch with 22 k gold solder. 

Small tubes are soldered perpendicularly to the labial surfaces of 
delicate iridioplatinum bands previously very carefully fitted to the 
crowns of the incisors. These tubes must be parallel with each other, 
with their incisal ends resting in contact with the middle segment of the 
arch. 

Very delicate spurs, of the length and diameter of the bore of the 
tubes, are soldered to the arch at points opposite the mouths of the 
tubes and at angles exactly corresponding to the bore of the tubes when 
the arch is in position. The ends of the spurs are then gently inclined 

Fig. 860 




forward about one-sixteenth of an inch by bending, the arch replaced 
upon the teeth, and the spurs sprung into the tubes. Thus, a gentle 
force from the elasticity of the spurs and arch is given to the roots of 
the teeth in a labial direction, while the crowns are given stationary 
support in all directions. The spurs are prevented from accidental dis- 
placement by filing a hook-like notch near the end of the spur which 
engages the end of the tube when sprung in position. 

The writer believes that such a gentle, harmless stimulus is thus 
given as will accelerate cellular activity and greatly lessen the time 
usually necessary for bone growth and retention, besides effecting final 
results in bone development which would otherwise be impossible 
when the patient is nearing maturity. 

The importance of the device has been verified in a case reported 
by Dr. A. H. Ketcham (Fig. 861), which shows the result in bone 
51 



802 



ORTHODONTIA 



growth after six months' wearing of the device, Fig. 860, showing the 
alveolar process at the time the device was adjusted. 

As the alveolar process is developed and the apices of the roots of 
the teeth are moved labially, it is occasionally necessary to renew the force 
by further outward bending of the spurs, and, in order to avoid the 
necessity of removing the arch and the possible accident of its unfavor- 
able bending, the writer recommends that a portion of the centre of the 
tubes be removed with a round file, as shown in the engraving. The 
arch may then be sprung slightly downward, the ends of the spurs 
caught with a delicate excavator where the tubes are cut away for the 
purpose, and given the necessary bend, then the spurs sprung back into 



Fig. 861 




position. This, however, should not be done oftener than once in one 
or two months. 

By studying the possibilities of this device it will be seen that we 
have absolute control over the development of the positions of the teeth 
in their entirety — far more so than by the use of any other known device : 

First, the most perfect support is given to the crowns of the teeth in 
all directions. 

Second, the crowns may be shifted labially or lingually, by tightening 
or loosening the nuts in front of the tubes of the anchor bands. 

Third, the positions of the roots of the teeth may be developed labially 
or lingually, mesially or distally, by gentle force from the proper bending 
of the spurs, independent of the position of the crowns. 

Fourth, force for rotation or for the prevention of rotation of any of 
the teeth may be given by partially flattening the ends of the delicate 
spurs and the ends of the tubes in which they are engaged, then giving 
the spurs a slight twist, and respringing them into position. 



RETENTION 803 

And finally, all of the teeth may at the same time be lengthened, if 
so desired, by giving the necessary downward spring to the segment 
of the arch. 

In like manner, support and movement may be given to the canines 
and premolars, if desired, and, by drilling through the sheaths of the 
tubes of the anchor bands and the sides of the threaded portion of the 
arch and inserting delicate keys therein, force may be exerted through 
the elasticity of the arch for the movements of the molar roots, either 
buccally or lingually. 

In making use of this device the arch may be placed above the tubes 
instead of below them, as shown, or, in favorable cases where the occlu- 
sion will permit, the arch may be placed lingually to the teeth, with the 
tubes either parallel with or at right angles to the long axes of the teeth. 
But, all things considered, the position given the device in the engraving 
will be found to be the most satisfactory. 

It is also equally applicable to the lower dental arch. 

This device may be operated either as a regulating or retain- 
ing appliance, or both, as its name implies. The writer believes 
its greatest usefulness will be as a bone stimulant, and when so used 
should be made very delicate, as described, so that only such gentle force 
will be given to the roots of the teeth as will physiologically stimulate 
the bone cells. Great force and rapid movement of the apices of the 
roots of the teeth the writer believes to be unphysiological. 

Fio. 862 




'« 



Retention of Cases Belonging to Class II. — In the retention of cases 
belonging to Class II the principal problem is to resist the mesial 
movement of the teeth of the upper arch and the distal movement of 
those of the lower arch, especially the canines, premolars, and molars. 
If there have been movements of individual teeth in other directions, 
as torsally, labially, etc., their movements may be resisted by methods 
which we have previously described for the retention of teeth in cases 
belonging to Class I. 

Our principal reliance is the application of force reciprocally between 
the teeth of opposing arches by means of intermaxillary retainers, shown 



804 



ORTHODONTIA 



in Fig. 862. This retainer is susceptible of numerous modifications 
to meet the requirements in different cases. 

It consists of a strong spur made to close in front of a plane of metal, 
both soldered to No. 2 bands, which are clamped in cement on opposing 
molars. 

The plane of metal, best cut from a silver ten-cent piece, should be 
about one-fourth of an inch long and one-eighth of an inch wide, and 
rounded on its distal angle. 

The spur is best made of nickel silver, about three thirty-seconds of 
an inch in diameter. 

The stress upon this device is often very severe, and unless carefully 
made and properly cemented upon the teeth it will give trouble by 
loosening. 

Bands of the best quality should be carefully fitted to the molars, 
and at their union with plane and spur should be strongly reinforced 
with plenty of solder, care being taken not to weaken the bands by over- 
heating. 

Both bands should be placed as near the grinding surfaces of the 
crowns of the teeth as possible, without interfering with occlusion, and 
the plane attached low down, or at the very edge of the upper band, and 
the spur attached as high up as possible on the lower band. In this 
way the spur is shortened and the leverage decreased, with the con- 
sequent danger of loosening minimized. The spur should always 
engage the plane on an incline, as shown in the engraving. It may 
occasionally be necessary to shift the position of the plane mesially or 
distally by resoldering to meet the requirements, as retention progresses. 



Fig. 863 



Fig. 864 



Fig. 865 





E. H. A. 



E. H. A. 



E. H. A 



This method of intermaxillary retention is also applicable to pre- 
molars and canines, as shown in Figs. 863 and 864. It may be used on 
these teeth in connection with molar retention, or independently, as 
occasion may require. It is often desirable to alternate from one to the 
other. The device as shown in Fig. 863 is incorrect, the spur shown, 
as being perpendicular instead of engaging the plane on a slight incline. 

When made use of upon the canine teeth no band or plane of metal 
is needed on the opposing (upper) canine, as the mesial incline of the 



RETENTION 805 

cusp of this tooth is taken advantage of. The flat spur should be grooved 
on its edge to make more secure its relation with the upper canine. 

It should incline somewhat forward to be most effective, and if 
occasional adjustment is necessary, this may easily be done by bending, 
to make its bearing upon the upper canine more effective. In this way 
not only retention, but the actual movement of the upper canine distally 
and the lower canine mesially, may be accomplished to some extent, 
and in many cases this is very desirable. 

Owing to the unfavorable shape for banding of the lower canine 
tooth, there is more liability of bands upon these teeth loosening 
under strain than those upon the premolars. They should therefore 
be made with the greatest care, always using H band material, and 
securing the most perfect fit. This spur is also best made from a 
silver ten-cent piece. The band is illustrated in Fig. 865. 

In rare instances spurs set in fillings for accomplishing the same pur- 
pose in retention will be found desirable, and Dr. Stanton makes use 
of a crown covering a tooth, which is fitted with an inclined plane at the 
desired point to engage the opposing cusp. The device would be effi- 
cient and especially applicable to the deciduous teeth, where the necessary 
reduction of the crown of the tooth in order to properly fit the metal 
cap would be permissible. 



Fig. 866 




E.H.A. 



The writer's plan of intermaxillary retention has been ingeniously 
modified by Dr. Griinberg, as shown in Fig. 866, and as in the use of 
this device the strain upon band and spur is quite equally divided, it 
will undoubtedly prove very efficient. 

For maintaining the proper width of the upper dental arch in the 
region of the premolars and to prevent the labial movement of the incisors 
which have been moved lingually in cases belonging to Division 1 of 
Class II and its subdivision, the lingual wire arch, shown in Fig. 857, 
is a favorite with the writer, in these cases taking advantage of the molar 
clamp bands that bear the planes of metal. The lingual arch here serves 
also another purpose, giving additional support to the molars. 

Very delicate gold bands encircle the incisors. They are provided 
with delicate hooks or staples on their lingual surfaces for securing 
their attachment to the arch by means of wire ligatures. The writer 



806 



ORTHODONTIA 



employs this means of attachment of the incisors in preference to the 
immediate engagement of the arch to the bands by solder, tubes, or 
spurs, as it admits of an easier adjustment and better control over the 
positions of these teeth, although some prefer hooks or staples soldered 
to the bands which directly engage the arch. Still, in many instances the 
writer prefers the simple wire ligature alone for securing the incisors 
to the arch, making the twist of the ligatures lingually to the teeth. 

Another plan, given to us by Dr. Kingsley, which has long been a 
favorite with many, is by means of a neatly fitting vulcanite or metal 
plate which covers the vault of the arch, shown in Fig. 867. This 
prevents the narrowing of the arch and also provides a means for the 
support of a screw in its anterior part. The screw is beaten thin where it 
passes between the central incisors, and is provided with a small button or 
cross-bar soldered to the end of the screw which is made to bear against 



Fig. 867 




the labial surface of the two central incisors. This is an efficient retainer, 
but the danger of its not being worn constantly by the patient makes 
its use far less desirable than that of a fixed device, yet it has long been 
a favorite with the writer in the last stages of retention. When used 
in connection with intermaxillary retention, the plate must be freely 
cut away to avoid interference with the screws of the clamp-bands. 

The working retainer, described on page 800 (Figs. 858 and 859), 
may also be used with much satisfaction for retaining the incisors in 
some cases belonging to this class. 

A device which may occasionally be used to advantage for resisting 
the labial and lengthening movements of the upper incisors is effected 
by placing upon the lower central incisors plain bands, having soldered 
to their labial surfaces strong spurs which project forward and are bent 
upward sharply at right angles to engage the labio-occlusal edges of 
the upper incisors, as shown on one tooth in Fig. 868. The stability 



RETENTION 807 

of the teeth used as anchorage should be reinforced by a section of the 
wire G, soldered across the lingual surface of their bands and made to 
bear against the adjoining lateral incisors. 

Sometimes it may be desirable to place the bands upon the canines 
instead of upon the incisors, and connect them by a bar of metal con- 
taining the retaining spurs, Fig. 869. 

If the reader will study this device he will observe that in its use 
not only is normal closure of the jaw compulsory, but that the incisors 
are kept compressed in their sockets and prevented from moving labially 
as well. Still another advantage of no small importance is gained in 
preventing the lower lip from being drawn against the lingual surfaces 
of the upper incisors, a habit which seems to be almost universal in 
these cases, and difficult but most necessary to overcome. 

For the second division of Class II and its subdivision the plan of reten- 
tion for the molars, premolars, and canines is the same as that already 
described for the retention of these teeth in Division 1, Class II, and its 
subdivision. 

Fig. 868 Fig. 869 





E. H. A. 

As the upper incisors in Division 2 are usually more or less crowded, 
rotated, and retruded in their relation to the line of occlusion, their 
requirements for movement, as well as the problems in their retention, 
are practically the same as for cases in which these teeth occupy similar 
malpositions in Class I. So their movements are readily combated by 
similar combinations of bands and spurs, as are also the anterior 
teeth of the lower arch. The working retainer may also be used in these 
cases, especially when there is found to be lack of development of the 
bone in the region of one or more of the incisors. 

Retention for Cases Belonging to Class III. — As in Class III the move- 
ments of the molars, premolars, and canines of both arches are the 
reverse of the movements of these teeth in Class II, the same plan of 
ntermaxillary retention, with the direction of force reversed, is employed, 
the spurs on the lower molars operating against the distal ends of the 
planes on the opposing teeth. It is frequently advisable to place the 
spur on the upper molars and the plane on the lower, in which case 
the spur operates against the mesial end of the plane. Dr. Griinberg's 
excellent modification of the plane and spur, previously described, will 
also be found very applicable. 



808 ORTHODONTIA 

The same results may be accomplished in simple Class III cases 
of very young patients by means of plain bands carefully fitted to and 
cemented on the upper central incisors, the bands having spurs soldered 
to their lingual surfaces which project downward and forward to engage 
the labial surfaces of the lower incisors, thus compelling the normal 
closure of the jaw and normal mesio-distal relations of the teeth. 

When individual movements of any of the anterior teeth have been 
accomplished they are retained by the application of bands and spurs 
in some of their combinations, as would be employed in similar problems 
found in Class I. 

The application of these principles of retention will be further dis- 
cussed in the treatment of individual cases. 



TREATMENT 

Preliminary Considerations. — Before beginning treatment of mal- 
occlusion of the teeth there should be certain well-defined principles 
fixed in our minds in regard to the dental apparatus as a whole, for 
we must constantly bear in mind the intimate relations existing between 
the teeth and all other tissues and parts of the dental apparatus, and 
the powerful influences they exert upon one another. We have seen 
that nature builds the human denture in accordance with her long- 
tried and well-established laws, the result being a constant and well- 
defined pattern ; that this pattern, although varied in form, is in principle 
always the same; and that its variations are always in harmony with 
the demands of the type of the individual. 

We have already noted that when nature, through certain adverse 
causes, is unable to fully carry out her normal processes in the building 
of the dental apparatus, there are in the result defects or variations from 
the normal plan, shown in malocclusion of the teeth, with consequent 
impairment of their functions — the extent of the malocclusion being in 
direct proportion to the extent of the disturbing cause — the perversion 
of the forces which are operative in building the normal denture. Also, 
in the same proportion as malocclusion exists, will there be disturbance 
in the harmony and balance of the mouth with the rest of the face. 

The longer teeth remain in malocclusion the more fixed becomes 
the variation from the normal in all co-related muscles and tissues. 
Logically, then, in the treatment of malocclusion our attention should 
be directed toward interpreting nature's designs and assisting her to 
carry out her original plan in the building of the denture, working hand 
in hand with her, for only as we comprehend her intent in each individual 
case and assist her, will our efforts be successful in establishing the 
normal in occlusion and the normal in the balance of the mouth with 
the rest of the face. It should be obvious, then, to all thoughtful minds, 



TREATMENT 809 

that the demand in treatment is the removal of pernicious causes, 
the retention of the full complement of teeth, and the compelling of 
their normal locking during or subsequent to their normal period of 
eruption, thus permitting nature to complete the denture and the 
co-related parts according to her fixed plan and the demands of the 
individual type. It is also obvious that the earlier our efforts at treat- 
ment are begun, the better we will be able to assist nature, and the 
more satisfactory will be the results. 

The method so long followed of determining an arbitrary course of 
treatment for each individual case "according to the judgment of the 
operator," in which extraction is freely resorted to, and the sizes of 
arches greatly reduced and their forms modified from nature's intended 
plan and the demands of the type, has ever resulted, and can only 
result, in establishing the abnormal — deformity. By such treatment, 
instead of greater freedom being given to the tongue and normal function 
to the teeth, the former is often more restricted and the function of the 
latter upon the whole rarely improved; and instead of establishing bal- 
ance, harmony, and beauty of the facial lines, the deformity is ultimately 
more often found to have been only modified, with a result even far 
less pleasing than the original condition. 

While in most instances we may rapidly establish the normal sizes 
of the arches and relations of the teeth, much time will often be required 
by nature to effect the normal development of the other tissues of the 
dental apparatus, the development of which has been arrested. Yet 
even in this we may often greatly assist nature by directing our patients 
as to the proper and necessary closure of their lips and teeth, and proper 
breathing, and by insisting upon their overcoming pernicious habits 
of the lips and tongue, and also insisting upon treatment of nose and 
throat when needed. These conditions often call for much tact and 
persistent patience on the part of the orthodontist. 

What we have said presupposes the treatment of cases with the full 
complement of teeth, which we have had the opportunity to treat during 
their most active period of growth, development, and eruption, or during 
the period in which lie our greatest opportunities for assisting nature in 
approximating the nearest to the ideal in the results. Yet many cases 
are presented for treatment in which there is a lack of the full comple- 
ment of teeth, through failure to develop, extraction, or caries. The 
demands for the great object to be accomplished, however, are the same 
in these cases as when the full complement of teeth is present, and 
necessitates the establishing of normal occlusion, or as nearly so as the 
exigencies of the case will permit, by enlarging the dental arches to 
their normal size and replacing the missing teeth by artificial substi- 
tutes. While this ideal treatment may not always be deemed advisable, 
it is impossible to lay down any rules for such exceptions. 

The carrying out of the ideal in the treatment of such cases presents 



810 ORTHODONTIA 

such apparently great difficulties that it would probably be the last 
one to which the amateur in orthodontia would naturally resort. He 
would be inclined to compensate for the already diminished size of one 
arch by reducing the size of the opposing arch by extraction. Yet 
the great difficulty of permanently maintaining the teeth in correct 
alignment when so treated must not be lost sight of, for it must be 
remembered that inclined occlusal planes, inharmonious as to size and 
form, are thus brought in contact, with teeth, also, at incorrect angles 
of inclination, thus tending toward their displacement from wrongly 
distributed force in occlusion, instead of occlusal planes harmonious as 
to size and relation with normal angle of inclination of teeth, as intended 
by nature, which favors permanency of normal positions and relations. 
Moreover, by the reduction of the sizes of the dental arches, the tongue 
and lips must exercise less control in keeping the teeth in correct posi- 
tions than when exerting their full normal influence, as when the full 
number of teeth is correctly placed. Furthermore, the invariable 
detrimental effect on the facial lines, the shortening of the bite, and 
the impairment of speech, make this plan of treatment so objectionable 
that it is rarely, indeed, that the skilful, modern orthodontist would 
resort to it, for the great perfection to which the regulating appliances 
have been brought makes easily possible the enlarging of the dental 
arches and the regaining of the spaces for the full mesio-distal diameter 
of malposed or missing teeth. This fact, together with the ease and 
permanency with which missing teeth are replaced, owing to the great 
advancement in modern prosthetic art, makes this the one plan of 
practice that will be more and more appreciated by the true orthodontist 
as his knowledge and experience increase; yet in the cases of very 
young patients, where there has been mutilation, it is often difficult 
to decide which of the two plans to follow, the serious problem hinging 
upon the result of mutilating sound teeth in order to restore missing 
teeth by artificial substitutes. Still, if it were always possible to have 
these restorations made with a very high degree of skill, with mutilation 
reduced to the minimum, the conservative, ideal plan of treatment 
would be universally desirable. 

Treatment of Cases. — Class I. — As we have already noted in the classi- 
fication of malocclusion, the number of cases belonging to this class is 
the greatest and comprises by far the largest variety, the distinguishing 
characteristic of the class being relative normal relations of the jaws, 
with molars in correct relation mesio-distally, although one or more 
may be in buccal or lingual occlusion. The malposed teeth are usually, 
however, confined to those anterior to the molars, and more commonly 
to the incisors and canines, the dental arches being smaller than normal 
and the teeth crowded and overlapping. Both arches are usually involved, 
and sometimes quite similarly. 

As the mesio-distal relations of the lateral halves of the dental arches 



TREATMENT 



811 



are normal in this class, it must follow that, if the malposed teeth of 
each arch be moved into harmony with the line of occlusion, the arches 
must then be in perfect harmony as to size, with harmony of the occlusal 
inclined planes of the cusps — normal occlusion — and with proper facial 
balance established. The latter, however, may not at once be apparent, 
as we shall see later, but it must follow ultimately when nature shall 
have effected the full development of the alveolar process 
and the muscles shall have become modified in form and 
function so as to act normally in their relation with the 
teeth in occlusion. 

To illustrate, Fig. 870 represents a type of malocclusion 
which, in its variations, is common in this class. It will 
be seen that the mesial and distal inclined planes of the 
mesio-buccal cusp of the upper first molar on the right 
are received between the inclines of the mesio- and disto- 
buccal cusps of the lower first molar, or that the relations 
of the first molars are normal. (The molars of the oppo- 
site side were also in normal relation.) The arches are 
diminished in size, and the teeth, especially the incisors, 
occupy positions lingual to the line of occlusion. What is then clearly 
indicated is that the arches should be enlarged and each tooth moved 
into its correct position in the line of occlusion, as shown in the 
case when completed (Fig. 871), and in the plan of treatment of 
any case, as has been said, it makes but little difference what 
positions the malposed teeth may occupy, they are always subject to 




E. H. A. 



Fig. 870 




the same general requirement. In the completed case, as shown in 
Fig. 871, it will be seen that each tooth has been placed in harmony 
with the line of occlusion, and is, therefore, now in best position to 
support and be supported by all the remaining teeth, as well as to be 
in best harmony with the muscles and to make possible the normal 
balance of the facial lines. 



812 



ORTHODONTIA 



Fig. 872 shows one of the most complicated types of cases belonging 
to this class. The teeth of both lateral halves of the upper arch are in 
lingual occlusion, the upper arch greatly narrowed and diminished 



Fig 871 




in size, with the laterals in marked torsolingual occlusion, and the 
centrals in torsal occlusion, while the great force received upon the 
molars, being wrongly distributed, has resulted in displacing all the 
buccal teeth of the upper arch bodily lingually, the apices of the roots as 



Fig. 872 




well as the crowns, with the opposite effect on the opposing teeth, thus 
greatly narrowing the upper jaw, dental arch, and nasal space, and 
widening the lower jaw, giving a peculiar bagginess to the lower part 



TREATMENT 



813 



of the face always noticeable in these cases. They are always 
progressive, usually beginning with the mal-locking of the first perma- 
nent molars, but sometimes preceded by similar malocclusion of the 
deciduous teeth. 

Fig. 873 




Had the first permanent molars received but a few hours' attention on 
coming into occlusion and been compelled to take their normal relations, 
doubtless the malocclusion would have ended there, and the eruption 
of the teeth and development of the alveolar process subsequent to this 



Fig. 874 




would have been along normal lines. Yet many dentists still persist 
in advising parents to defer treatment of their children's malocclusion 
until all of the teeth have erupted. 

The line of treatment was toward the ideal, widening the upper 
arch, correcting the malpositions of the incisors, and narrowing the 
lower arch. 



814 



ORTHODONTIA 



Fig. 874 shows the upper arch being widened by means of the expan- 
sion arch, adjusted in the usual way, and reinforced by one of the 
spring levers, L, the incisors being moved forward en masse and rotated 
by means of spurred bands, ligatures, etc., all as shown and described 
in the section on Adjustment and Operation of Appliances. 



Fig. 875 




The narrowing of the lower arch was effected by means of a device 
manufactured for the occasion and shown in Fig. 873 ; but the recent 
practice of the writer is to narrow the dental arches in such cases with the 
expansion arch (ribbed), it having been found that it develops ample 
force for this purpose. 



Fig. 876 




In making use of the ribbed arch, as above, it is only necessary to 
compress its sides so that they are perhaps two-thirds the width of 
the dental arch to be narrowed, and insert the ends in the sheaths of the 
D bands, as usual, care being taken to retain all of the spring in the 



TREATMENT 



815 



lingual direction possible. The arch is prevented from springing forward 
by being secured to the incisors by one or more ligatures. Although its 
action is slow, requiring several weeks in a patient, aged sixteen years, 
the writer has found its use most satisfactory. 

Fig. 875 shows the upper arch completed and the retaining devices 
in position, while Fig. 876 shows both arches completed and the teeth 




in occlusion. The lingual tendency of the upper incisors and the torso- 
infra-occlusal tendencies of the upper canines, as well as the lingual 
tendency of the molars and premolars, were resisted by bands on the 
canines connected by a section of the wire G, and a vulcanite plate, as 
illustrated. The bands upon the canines are also shown in Fig. 876. 



Fig. 8 




As here shown, the retaining wire rests on the incline of the lingual 
marginal ridges of the incisors. It should bear either above or below 
this incline, for if allowed to rest in the position shown, delicate bands 
would be required on the laterals, at least, to prevent the wire from 
being forced toward the cutting edges of the teeth. 

The lingual retaining arch, as shown in Fig. 857, would often be 
preferable to the bands and plate in such cases, and the working retainer 



816 



ORTHODONTIA 



might also be used, and doubtless in many similar cases would be 
preferable. 

The model illustrated in Fig. 877 represents a case where one only 
of the lateral halves of the upper arch was in lingual occlusion. The 
lateral incisors were in marked torso-lingual occlusion. The patient 
was a child, aged eight years, the deciduous molars and canines being 
still in position. 

The plan of treatment clearly indicated was widening the arch by 
movement buccally of the teeth on the affected side only, with labial 
movement of the centrals and torso-labial movement of the laterals. 
Fig. 878 shows a view of this arch from the occlusal aspect, with the 
appliances for accomplishing these movements of the teeth in position. 



Fig. 879 




It will be seen that all of the teeth on the left side are used as anchorage, 
and that their combined resistance is concentrated, through the force 
distributed by the external and internal arches, upon the left first per- 
manent molar. But a few days were necessary to move this tooth into 
correct position, where it was maintained by occlusion and the modified 
(through bending) alveolar process. A wire ligature was then made to 
encircle the second deciduous molar and the expansion arch, thus 
practically transferring the force to this tooth. Later, the first deciduous 
molar was moved out in the same way. The object of moving the teeth 
one at a time was to avoid overtaxing the anchorage derived from the 
opposite side of the arch. Had the effort been made to move all at the 



TREATMENT 



817 



same time, it is probable that the teeth on the normal side would have 
been displaced more rapidly than those on the abnormal side, on 
account of the increased resistance offered by the inlocking of the 
inclined planes of the cusps of the molars on the abnormal side. The 
writer's latest plan for avoiding displacement of the teeth used as 
anchorage in cases of this kind is to enlist stationary anchorage by 
uniting the sheath of the clamp-band and the threaded portion of the 



Fig. 880 




arch within it with soft solder, thus requiring the displacement of the 
anchor tooth bodily, if moved at all. It will be readily understood how 
greatly the anchorage would be thus increased. 

While the appliances were acting upon the abnormal lateral half of 
the arch, the incisors were carried forward and rotated by bands, 
spurs, and ligatures, with notches on the ribbed expansion arch to pre- 
vent slipping of the wire ligature, the movement being further assisted 
by the tightening of the nut on the expansion arch on the affected side. 
52 



818 



ORTHODONTIA 



The widened arch was retained by a vulcanite plate (Fig. 854). 
The mesial, torsional, and lingual tendencies of the right lateral and 
the lingual tendencies of the other incisors were resisted by bands upon 
the laterals connected by a piece of wire, G, soldered to their lingual 
surfaces. Fig. 881 shows the occlusion of the teeth eight years after 
treatment. The facial lines were practically faultless. 

This type of malocclusion is more frequent among children than 
seems to be commonly supposed, and it is important that it receive early 
attention, for if allowed to progress the mouth must inevitably develop 
asymmetrically, the jaw shifting laterally, giving a peculiar twisted 
appearance to the mouth. 



Fig. 881 




Figs. 879 and 880 illustrate a case in its labial, buccal, and occlusal 
aspects, and from the position of the canines and that of the mesio-buccal 
cusps of the upper first molars it will be readily recognized as a typical 
case belonging to the first class. 

It will be seen that the arches are much shortened and reduced from 
the normal size, with marked lingual positions of all the incisors, the 
left upper lateral being in contact with the first premolar, causing almost 
complete labial displacement of the left canine, while at least one-half 
of the space necessary for the right canine is occupied by the right lateral, 
the influence of the lips effectually maintaining the diminished size 
of the arches and the malocclusion. 

The effect, as might be supposed, was very noticeable in the facial 
lines of the patient, as shown in Fig. 732, producing, as we have seen, 
a pinched and flattened appearance about the mouth. 



TREATMENT 



819 



What was clearly indicated was to place all the malposed teeth in 
harmony with the line of occlusion. 

Fig. 882 shows the various necessary tooth movements being accom- 
plished in both arches simultaneously by means of ribbed expansion 
arches/ D bands, spurred bands, wire ligatures, etc., adjusted and 
operated as described in the section on Adjustment and Operation of 
Appliances. 

The anchorage was effected by means of D bands placed upon the 
first molars in the lower arch, while in the upper arch a D band upon 
the first molar was used on the right side and an X band on the first 



Fig 882 




premolar on the left side, it being found necessary after a few days of 
treatment to transfer the anchorage from the left first molar to this 
tooth, as the molar showed displacement distally in resisting the strain 
of the labial movement of the incisors. It is not surprising that the 
first molar did show weakness of anchorage and move distally in this 
case, as it may in all cases at this age, for the reason that the second 
molar gives it no support, it being still unerupted and lying in a large 
open crypt into which the first molar may quite readily be moved. It is 
usually well in such cases to reinforce the molar, which can easily be 
done by ligating it to the premolars. 



1 Several of the cuts showing the expansion arch were made before the invention 
of the ribbed expansion arch, therefore soldered spurs on the plain arch to prevent 
the slipping of the ligatures are shown instead of notches in the ribbed arch, as now 
used, but referred to in the text as though the notched ribbed arch had been used. 



820 ORTHODONTIA 

It will be noticed that there are two ligatures upon the left lateral 
incisor (upper). One is a plain ligature, as in A, Fig. 807, for effecting 
the labial movement; the second, as in B, Fig. 807, encircles the arch 
and a spur soldered low down upon the lingual surface of the band 
upon the lateral. The office of this ligature was partly to assist in 
carrying the incisor forward, but principally to effect its rotation. A 
notch in the rib of the expansion arch prevented this ligature from slid- 
ing forward and directed the movement of the tooth laterally, the arch 
being so bent that in shape and spring it bore toward the left and favored 
this movement, assisted reciprocally by the band, spur, and ligatures 
upon the right lateral. The reason for the spurs being placed well 
toward the gum, as is important in all such cases, is that it resists the 
tendency of the arch to slide toward the occlusal edges of the teeth. This 
tendency is further opposed by crossing the strands of the ligature near 
the spur during the adjustment of the ligature. 

The right upper central is also encircled by a ligature, which is pre- 
vented from sliding off the tooth by the hand. 

The form of the expansion arch was occasionally modified by 
bending to meet the requirements of the moving teeth and prevent 
bunching. 

Owing to the lingual inclination of the crowns of the lower incisors no 
bands on them were necessary, the ligatures simply encircling the expan- 
sion arch and crowns of the teeth. It will be noted that a notch in the 
ribbed arch directed the movement of the canine laterally as well as 
labially. 

The slight necessary rotation of the left second premolar was accom- 
plished by bands, spurs, ligatures, and rubber wedges, as already 
described, as soon as the anterior teeth had been moved into correct 
position to reduce the crowding and permit it to turn. Fig. 882, made 
from a study model taken in wax with the appliances in position, shows 
the movements of the teeth nearing completion, where they were tem- 
porarily retained pending the eruption of the upper canines. 

The teeth of the upper arch were permanently retained in their new 
positions by a section of wire G, soldered to the mesio-lingual angles 
of bands on the canines and made to bear against the lingual surfaces 
of the intervening incisors, as in Figs. 846 and 892. 

The corrected positions of the lower canines and incisors were main- 
tained also by a similar device. 

The lesson we would especially impress in the treatment of this case 
of malocclusion is the important one of growth and development of the 
alveolar process subsequent to the movement of the teeth and the estab- 
lishment of normal occlusion, for unless nature is induced to complete 
the growth of the bone which has so long been arrested, it will be im- 
possible to maintain the teeth in their corrected positions, or to establish 
the proper contour of the face. In this case we were fortunate, for 



TREATMENT 821 

after two years of retention it will be seen by comparing Fig. 883, which 
shows the upper model of the case soon after the completion of tooth 
movement, with Fig. 884, which shows the case nearly two years later, 
how pronounced and gratifying has been the growth and development 
of the intermaxillary bones in the region of the roots of the incisors, 
and the shifting of the very apices of the roots of these teeth as well. 

Fig. 883 




Fig. 733 represents the face of the patient at this time, and the 
improvement in the facial contour is also very noticeable and gratifying. 
Let the reader picture in his mind what would have been the result had 
extraction been resorted to in the treatment of this case — a practice 



Fig. 884 




still insisted upon by many. The function of occlusion would have been 
greatly impaired, the sizes of the arches diminished, and the tongue 
restricted, with the deformity pronouncedly manifest in the irreparably 
impaired facial lines. 

In the case represented in Figs. 885, 886, 887, and 888 the same 



822 



ORTHODONTIA 



general plan of treatment and retention was followed as in the last case, 
and the very gratifying results in occlusion and bone development, and 



Fig. 885 





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. 






: 














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... 








vf 
















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the excellent harmony in balance of the facial lines of the patient three 
years later are shown in Figs. 889 and 890. 



TREATMENT 



823 



Had the working retainer been employed in both of the cases last 
shown, the same or possibly better results would have been accom- 
plished, with a far shorter period of retention. 



Fig. 887 




Fig. 888 




824 



ORTHODONTIA 



Fig. 891 shows a case, also belonging to this class, in which there is 
much space between the occlusal edges of the incisors, the result of the 
habit of holding the tongue between the teeth. The cut also shows 



Fig. 




Fig. 890 




TREATMENT 825 

the method of correcting the infra-occlusion of the incisors by means of 
the expansion arch. The middle of each side of the expansion arch was 
made to bear against a spur soldered tc a band on the canine, which 
acted as a fulcrum, the centre of the arch being sprung over hook-like 
spurs projecting from the labial surfaces of bands on the incisors, and 
in its spring thus exerting a downward force upon them. Spurs, in 
connection with the bands on the incisors, for engaging the expansion 
arch, are now dispensed with, as better control of the amount of force 
to the moving teeth can be gained with a ligature as a medium of 
attachment, the bands being used only to prevent the ligature from 
slipping off the tooth. The ligature is placed about the neck of the tooth 
and given one twist, the arch sprung up and engaged with the ligature, 
which is then given another twist. 

Fig. 891 




EMA 



In many instances the bands may also be dispensed with by placing 
a ligature about the neck of the tooth above the gingival ridge, twisting 
it in the usual way, then cutting the ends off short. The ligature is 
then conformed still more closely to the size of the neck of the tooth by 
giving it a final set or part of a twist with the How pliers. Another 
or independent ligature is then passed between the neck of the tooth 
and the first ligature and made to engage the latter and the expansion 
arch, for giving the downward tension upon the tooth. Either of the 
arches E or the arch B may be used. 

In correcting infra-occlusion of the teeth by this excellent method, 
it has been found that the spurs acting as fulcrums are unnecessary, the 
spring of the arch gained through the pry of the sheaths of the anchor- 
bands usually being ample. It is well, however, to reinforce this 
anchorage with intermaxillary anchorage; that is, stretching delicate 
rubber ligatures from hooks attached to the upper expansion arch to 
others upon the lower expansion arch, or to attachments on the lower 
canines as in Fig. 892. 

The best means of retaining teeth so elevated is to allow the expan- 
sion arch to remain in position the requisite time. 

Fig. 893 shows another case of pronounced infra-occlusion of the 



826 



ORTHODONTIA 



incisors, canines, and premolars, principally of the upper arch. This 
condition was augmented by the slight supra-occlusion of the second 
molars, they being the only teeth that came in contact when the jaws 
were closed. 



Fig. 892 







The plan of treatment which seemed most advisable was the short- 
ening of the second molars and the lengthening of all the incisors and 
canines. This was accomplished by means of the spring of the expan- 
sion arches reinforced by intermaxillary anchorage, exactly as described 
in the last case. 



Fig. 893 




All of the lower incisors and canines and the upper lateral incisors 
and canines were banded with delicate neatly fitting bands made from 
the thinnest band material (C). These bands were to prevent the 
ligatures from slipping off the teeth. This was necessary, as the shapes 
of these teeth were not favorable for retaining the ligatures twisted above 
their gingival ridges, as suggested in connection with the case last 
described, but the shapes of the upper centrals being favorable, no 
bands were needed on them. The finest of the three sizes of wire 
ligatures were used in ligating the teeth to the expansion arches, after 



TREATMENT 



827 



the latter had been bent to give the greatest downward spring to the 
upper and upward spring to the lower. The force from this spring was 
intensified by two of the delicate rubber ligatures, which were stretched 
from one arch to the other and made to engage spurs which had been 
soft-soldered to the expansion arches opposite the canine teeth. 

It will be noted that the left lower first molar is in buccal occlusion, 
and that its antagonist is in lingual occlusion. The expansion arches, 
before insertion, were bent to give spring for the correction of these 
positions. 

After the movement of the teeth had been continued for about six- 
months a period of rest was given the patient to await the growth of 
the alveolar process, during which time retention of the teeth was 
effected simply by allowing the arch and ligatures to remain passively 



Fig. 894 




in position. The case was of course occasionally inspected to make 
sure that all bands and ligatures were in order, and at the end of the 
period of rest the development of the tissues was noticeable and gratifying. 
The expansion arches were removed and, after bending them to give 
the necessary spring, they were reinserted and tension again given to 
the teeth through the adjustment of ligatures, as previously. After 
continuing the movement very slowly for three months more, an impres- 
sion was taken of the labial and buccal surfaces of the teeth while in 
occlusion, as illustrated in Fig. 894, which truthfully indicates the re- 
lations of the teeth at this time. 

Further movement of the teeth seemed unnecessary. The patient 
was again dismissed with instructions to return for occasional inspec- 
tion of her teeth, which were retained as formerly by means of the arch 



828 



ORTHODONTIA 



and ligatures. These were worn for about a year and then removed. 
No unfavorable movements of the teeth recurred. 

Great caution should be observed in all such extensive operations for 
elevating the teeth not to excite inflammation or to move the teeth too 
rapidly. The movement should be very slow, but continuous, otherwise 
there will be great danger of destroying the pulps. This should be ap- 
parent when we remember how extensive must be the changes in the 
peridental membrane and alveolar process, and what a severe strain 
is put upon these tissues incident to effecting such great changes in the 
positions of the teeth. 

Such cases present many points of interest, especially the readiness 
and completeness with which the gum tissues, and probably to some 
extent the alveolar tissues, follow the teeth in these extensive move- 




ments. It is doubtful whether the treatment of these cases should 
ever be undertaken after maturity, although we have as jet nothing 
but theory to suggest fear of alveolar disintegration as a result later 
in life. Another is that a surprisingly large percentage of cases of this 
type show the effect of some serious systemic disturbance early in the 
development of the enamel of the incisors and first molars, strongly 
suggesting the closer study of the early history of these cases if we would 
learn their cause. 

That this case might have been treated more satisfactorily from begin- 
ning to end by means of the working retainer device shown in Figs. 858 
and 859. 

Fig. 895 shows the buccal aspect of a case of malocclusion before 
and after treatment, the cause of the malocclusion being mutilation by 



TREATMENT 829 

extraction. The occlusion on the right side was normal. On the left 
(upper model) the lateral halves of both arches were shortened, the 
upper permanent lateral incisor being in contact with the first premolar. 
There was a shrunken appearance of the mouth, and the incisors were 
shifted from the median line. This condition was the result of the un- 
fortunate and unnecessary loss of the deciduous upper canine and the 
first and second deciduous lower molars. 

It needs but slight reflection to realize what must follow as the result 
of this loss. The permanent upper canine on erupting must be forced 
into pronounced labial occlusion, with marked disturbance of the left 
lateral and central, while in the lower jaw marked malocclusion must 
follow the eruption of the premolars. 

The treatment clearly indicated was the lengthening of the left lateral 
halves of both arches the full amount of the missing teeth by carrying 
forward and laterally (to the right) all the incisors. 

Fig. 896 




This was accomplished in both arches simultaneously by means of 
expansion arches, bands, and ligatures. No bands on the teeth to be 
moved were necessary. The incisors were laced to the arch with plain 
ligatures, as in A, Fig. 807. The notches in the ribbed arches for pre- 
venting the ligatures on the upper lateral incisor and lower canine from 
slipping were placed about opposite the middle of the centrals, so that 
force produced by tightening the nuts in front of the anchor sheaths on 
the first molars exerted a direct mesio-labial movement of these teeth, 
and as the nuts were tightened only on the affected side the lateral 
shifting of the incisors, as the arches were lengthened, was natural and 
easy. 

The result of treatment is shown in the lower model, the sides of 
the arches having been sufficiently lengthened to admit of the eruption 
of the upper canine and lower premolars. 

Retention of the space for the premolars in the lower arch was effected 
by means of the device shown in Fig. 837, and for the upper canine as 
shown in Fig. 838. These were worn until the eruption of the teeth 



830 ORTHODONTIA 

made their use no longer necessary. This is a very desirable method of 
retention in all similar cases. 

On the right of the engraving (Fig. 896) is shown the model of a 
case from which several valuable lessons may be learned. The case 
was that of a girl, aged sixteen years. Two years previous to the 
making of this model the occlusion of her teeth was practically fault- 
less, and, with the exception of the left lower first molar her teeth were 
of excellent structure and color. At this time this molar was lost 
through extraction. Then progressively followed the perversion of the 
normal forces : 

1. The tipping forward of the second molar — the inevitable result. 

2. The shifting distally of this lateral half of the mandible. 

3. Pressure from the lower lips, which, in connection with the shifting 
distally of the mandible, would soon move into complete distal occlusion 
the teeth in this lateral half of the lower jaw anterior to the space. 

4. Pressure from the upper lip has gradually moulded the upper arch 
to conform to the diminishing size of the lower, as shown by the bunching 
of the upper incisors. 

In connection with this case attention was called for the first time in 
literature to the shifting distally of the mandible as one of the results 
of extraction of the first permanent molar. 1 It should be explained 
that this must result as the fixed relations of the crown through the in- 
clined occlusal planes with those of the opposing teeth, so that in reality, 
instead of the crown of the lower second molar tipping forward, as it 
appears to do, the mandible and the apices of the root of this tooth 
move distally, following the line of least resistance. Later the restrain- 
ing influence of the occlusion would be wholly lost. Then the actual 
tipping forward of the crown of the tooth will occur, as in Fig. 897. 

The treatment clearly indicated was the lengthening of the lateral 
half of the lower arch, the tipping to an upright position of the second 
molar, and the correction of the positions of the teeth in the upper arch, 
or the restoration of the occlusal planes of all of the teeth to their original 
positions, as is shown in the model of the completed case on the left of 
the engraving Fig. 896. 

The patient was then referred to her dentist for an artificial substitute 
for the lost molar, which, being provided in the form of a bridge, served 
the double purpose of retention and mastication. The requirements 
of orthodontia and bridging are such as should induce a closer study of 
their relations, and if, before making bridges for their patients, dentists 
would refer them to competent orthodontists, better results would very 
often follow. The placing of bridges on leaning piers is unmechanical, 
and, as applied to the mouth, is also unphysiological. 

A point we would emphasize in relation to this case is that the changes 

1 Angle, Malocclusion of the Teeth, sixth edition. 



TREATMENT 



831 



taking place in this previously faultless arch, as the result of the loss of the 
first molar, are such as must and do always follow the loss of this tooth. 
Examine a thousand similar cases, and as many similar results will be 
found. 

It will be noticed that in the model on the right none of the teeth on 
the left side occlude, but that they merely touch at irregular intervals, 
and are practically worthless for mastication. What we would especially 
emphasize in this connection is that the lost tooth must be immediately 
replaced by some form of artificial substitute, or the serious impairment 
of the occlusion of the remaining teeth on the side of the arch from 
which the tooth has been extracted will certainly follow. 



Fig. 897 




As the same plan of treatment was employed for accomplishing the 
various necessary tooth movements in this case as in overcoming the same, 
but more complicated, problems in the case next to be shown, they will 
be described in connection with that case. 

Figs. 897 and 898 show a most unfortunate result from both right and 
left sides, following the extraction of the four first permanent molars, 
which, though perfectly sound, were removed at the age of nine years, 
with the idea of making space to prevent malocclusion of the other teeth, 
and how successful was the effort is readily seen. The result is but 
natural. Not only have the remaining teeth been rendered almost useless 
for mastication, but in recent years there has been chronic pericementitis, 
resulting from the wrongly directed force upon the molars in their tipped 
and abnormal positions. The facial lines were also greatly marred by 
the arrest in the development of the alveolar process, as shown on the 
left in Fig. 741, for without the wedging influence of those most important 



832 



ORTHODONTIA 



teeth — the first molars — the teeth anterior could not be pushed forward 
by the eruption of the second and third molars, which is necessary for 
the proper contouring of the face. 

Gold capping of the leaning molars, resorted to by the patient's 
dentist in this case to improve the occlusion, only aggravated the condi- 
tion, for the gold crowns only gave a longer leverage, thereby increasing 
the force through occlusion for the further tipping of the teeth. 

There was but one logical and rational plan of treatment, namely, 
to regain the lost spaces of the four molars by carrying all the teeth 
anterior to them forward, and those posterior to them somewhat distally 
and to an upright position, and replace the missing teeth by artificial 
substitutes. 

Fig. 




To accomplish this all four second molars were carefully fitted with 
D bands, the sheaths on the lower bands being resoldered to align 
properly with the expansion arch. The ribbed expansion arches were 
then carefully bent to conform to the outside of the dental arches, and 
were inserted without lateral spring in the sheaths of the clamp bands, 
as widening the dental arches was not necessary. 

The central and lateral incisors of the upper arch were then ligated 
to the upper expansion arch, the simple ligatures, as in A, Fig. 807, 
being employed, and in like manner were the lower incisors attached 
to the lower expansion arch. 

Hook-like notches were then filed in the ribs of the expansion arches 
directly opposite the space between the lateral incisors and canines. 
Next strands of the heaviest ligature wire were looped over the distal 
surfaces of the second premolars, the ends brought forward, and the end 
of each lingual strand passed through between the canines and lateral 



TREATMENT 833 

incisors, and the two ends of each strand made to engage their notch 
in the rib of the expansion arch, just described, firmly drawn, and given 
three-fourths of a twist, the surplus wire cut off, and the ends bent out 
of the way, as usual, thereby at once exerting tension in a mesial direction 
on all the second premolars, which, in turn, was transferred to the first 
premolars and canines, with a labial movement of the centrals and 
laterals. This force was, of course, transmitted in the opposite direction 
to the second molars, and, in turn, to the third molars. The nuts 
of the expansion arches were tightened by giving them one revolution 
twice a week. The result was the gradual carrying forward of all the 
teeth anterior to the spaces, and at the same time the movement of all 
the molars distally. 

The most difficult problem apprehended was to gradually effect at 
the same time the tipping to an upright position of the greatly leaning 
lower second molars. Yet this was easily accomplished by bending 
each end of the lower expansion arch downward, slightly, at a point just 
anterior to the nuts on the same, so that when the arch was inserted in 
the sheaths of the anchor bands and the anterior part of the arch was 
drawn up and ligated to the incisors, there was a pry upward on the 
mesial ends and downward on the distal ends of the sheaths of the 
lower anchor bands, which being transmitted through the tightly clamped 
bands to the teeth, the effect was to rapidly tip the molars upward and 
backward. 

As the movements progressed, the spring of the arch from the upward 
pry gradually became insufficient, necessitating the removal of the 
lower D bands and the resoldering of their sheaths in order to 
again intensify the force and cause the further tipping distally of the 
molars. 

As it was desired to carry all of the teeth anterior to the spaces well 
forward, the force necessary was so great that before the movement 
of these teeth was completed the molars had been carried to an upright 
position and as far distally as was necessary. Their further movement 
was then arrested by so bending the ends of the arches as to occasion 
their binding in the sheaths and prevent further tipping distally of the 
molars, or changing the anchorage from simple to stationary. 

The retention in this case now would be to allow the regulating appli- 
ances to remain passively upon the teeth a short time, replacing them 
later by the lingual arch retainer, shown in Fig. S57, and finally removing 
it and replacing the missing molars by proper bridges. 

Notwithstanding the advanced age of the patient (thirty-eight years), 
supposedly unfavorable for the treatment of malocclusion, it being the 
most advanced age recorded for such an extensive operation, the writer 
was agreeably surprised to find that the teeth were moved quite as easily 
and fully as rapidlv as is usual in the case of a miss of eighteen, and with 
no unfavorable symptoms following the movement of any of the teeth. 
53 



834 



ORTHODONTIA 



The result in occlusion is shown in Fig. 899. It will be seen that 
all of the teeth anterior to the space have been carried well forward and 
that the molars have been moved distally and into correct relations. 

The remarkable changes in the sizes of the arches and in the relations 
and inclinations of the teeth are naturally reflected in the lines of the 
mouth as related to the other features, as will be noted by comparing the 
face after treatment (on the right in Fig. 741) with its condition before 
treatment (on the left in Fig. 741). Yet great as are the changes in the 
facial lines, the close student will observe that there is still not complete 
normal contour of the mouth, which, as we perceive, is but natural 
when we remember how the arches were robbed in youth of that normal 
wedging influence of the first molars, so necessary to effect the normal 
development of the bones of the face and its consequent normal contour, 
which could not be wholly regained so late in life. 

Fig. 899 




Another point of great interest in connection with this case is the posi- 
tive proof that even in this remarkable case the second upper molars 
had not moved forward farther than their normal positions, notwith- 
standing the early loss of the first molars. 

Other cases belonging to this class, almost innumerable, might be 
cited, but as their variations from the cases already shown would be 
principally in degree, with the same general plan of treatment, it is 
unnecessary to do so. 

Treatment of Cases, Class II, Division 1.— It will be remembered 
that the distinguishing characteristics of cases belonging to this 



TREATMENT 835 

division of this class are distal occlusion of the teeth of both lateral 
halves of the lower arch, with more or less deformed and underdevel- 
oped mandible, narrowed upper arch, and protruding upper incisors. 
It will also be remembered that those afflicted with this type of 
malocclusion are in almost every instance affected with some form of 
nasal obstruction necessitating mouth breathing, which usually begins 
at an early age, causing the mouth to be held open almost constantly 
and the lips and buccal muscles to act abnormally. In the effort 
to breathe, the upper lip is drawn upward and fails to develop in 
size and function, exercising little restraint upon the labial movement 
of the incisors. Their protrusion, therefore, becomes more and more 
pronounced, partially as a result of pressure from the tongue and narrow- 
ing of the arch through malocclusion and the action of the buccal muscles, 
but principally because the lower lip is so frequently forced against their 
lingual surfaces in swallowing and in the effort to moisten the mucous 
membrane of the mouth. The lower incisors become lengthened, prob- 
ably from lack of function, so that their occlusal edges are in many cases 
in contact with the mucous membrane of the hard palate. 

It is commonly supposed that this form of malocclusion is the result 
of overdevelopment of the upper jaw. The writer has never seen a case 
where this condition existed, neither are the teeth of the upper jaw 
" inherited too far forward," as is pointed out in the chapter on Occlusion. 

The narrowed upper arch and protruding upper incisors, the lower 
jaw abnormal in form and distal in relation, the arrest in the develop- 
ment of the nasal apparatus, the modification in form and function of 
the nose and muscles, and the marred facial lines are but the natural 
results of the failure of the first permanent lower molars to lock normally 
at the time of their eruption, accompanied and probably preceded by 
pathological conditions of the nose or throat that established the habit 
of mouth breathing. It is interesting to note the gradual and progressive 
development of cases belonging to this class — the result of perverted 
forces in this combination. It seems reasonable to believe that the 
mandible is prevented from developing normally through the distal 
locking of the teeth and the consequent abnormal distribution of force 
from the muscles and the force of occlusion. Normally the force is 
distributed on the line of the long axes of the teeth, but when the lower 
molars lock in distal occlusion the force is received principally upon 
the anterior half of their crowns, as show r n in Fig. 900, the tendency being 
to drive their apices distally, or at least to prevent their normal move- 
ment forward, which would also prevent the normal growth and lengthen- 
ing of the mandible. This seems hitherto to have been unnoted, yet it 
seems most probable when we consider how pronounced is the interference 
with the normal growth of the mandible, maxilla, and alveolar process, by 
the abnormal distribution of force in those cases where the upper teeth 
on erupting lock in lingual occlusion. 



836 



ORTHODONTIA 



Cases belonging to this division usually begin with the mal-locking of 
the first permanent molars at the time of their eruption, although we now 
know that they may be established much earlier, or during the develop- 
ment of the deciduous denture, and this is not remarkable, since nasal 
obstructions from adenoid growths and other causes are often well 
defined at two and three years of age. This may be so slight at first as 
to occasion mouth breathing only at intervals and later disappear entirely, 
but. if sufficient at the time of the eruption and locking of the deciduous 
teeth, or of the first permanent molars, to decide the distal locking of the 
cusps of the teeth — and but a few days would be necessary to accom- 
plish this — the nucleus of conditions would be established which must 
progress until all of the conditions of a typical case of either the first or 
second divisions of this class have developed. Or, if the distal locking 
should occur only on one side, the case would belong to the subdivision 
of either the first or second division. 



Fig. 900 


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m 


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.^y%ks*#^pPijJ|^J 


*Wm 


'* Mk*:' -- <■ »*'*>'''3Myj 


mmmmmmKm 



Once established, it is remarkable what similarity exists between the 
cases of each division, especially those of the first, the differences being 
chiefly in degree, which is usually in proportion to the age of the patient. 
And, as we have already noted in the section on Facial Art, the disturb- 
ance in the balance of the facial lines is very characteristic and in direct 
proportion to the degree of the malocclusion. 

That we may the more intelligently decide as to the proper plan of 
treatment in these cases, there is another question which is well worthy 
of consideration, and it is the inharmony in the relations of the opposing 
planes of the teeth in their distal occlusion. Apparently this is not great, 
judging from a superficial examination of the buccal relations when the 



TREATMENT 



837 



jaws are closed, as is well illustrated in Fig. 900, or any similar case, but 
in reality it is very great, for it must be remembered that each occlusal 
plane has a special form designed by nature to beautifully match and 
harmonize with its natural opposing plane, to be most efficient in occlu- 
sion and function, as we have seen in studying the normal. But with 
the teeth in distal occlusion, each inclined plane is opposed by one in- 
harmonious in form and relation, with far less inefficiency in occlusion 
and function. This is better shown by a study of the lingual aspect of 
this same case shown in Fig. 901. It would be hard to estimate how 
greatly the efficiency of the molars is thus impaired. 



Fig. 901 




The writer is more and more impressed with the belief that this 
lessened efficiency, and perversion of the occlusal forces has much to do 
with the maldevelopment of the mandible in these cases. 

The modern, logical plan of treatment of cases belonging to this division 
is to divert from abnormal to normal action the forces which are oper- 
ative in producing the deformity, or, first to remove the cause by proper 
treatment of the nose, making normal breathing not only possible but 
actual, and then to establish the proper relations of the occlusal planes of 
the teeth — normal occlusion — beginning with the correction of the mal- 
positions of the first molars, and following in the order of the teeth 
mesially, ending with the incisors, instead of beginning with the protrud- 
ing upper incisors, the symptoms, as it were, as in the old plan of treat- 
ment of which we shall speak later. Then retaining the teeth until all 
of the tissues and muscles involved shall have become normal in growth 



838 



ORTHODONTIA 



and harmonious in function through their mutual cooperation. Natu- 
rally the earlier the treatment, the more perfect must be the ultimate 
result. 



Fig. 902 




Fig. 903 




This plan of treatment is illustrated in the following typical average 
case — that of a girl, aged thirteen years. The case is shown from the 
buccal aspect of the right and left sides in Figs. 902 and 903. The 



TREATMENT 



839 



molars, premolars, and canines in both lateral halves of the lower jaw 
have erupted and locked in distal occlusion, with consequent inharmony 
in the sizes of the arches and a corresponding inharmony as to the size 
of the mandible, also resulting in exactly proportionate disturbance of 
the beauty and balance of the facial lines, as shown by the profile in 
Fig. 904. 

To establish normal occlusion it was necessary to tip the crowns of 
all the lower teeth forward and those of the upper arch distally, suffi- 
cient to establish the normal mesio-distal relations of the inclined occlusal 
planes. The degree to which the teeth of each arch shall be moved 
varies in different cases. Usually the movement should be about equal 
in each arch, for reasons to be noted later. 



Fig. 904 




The anchor bands D were carefully fitted to all four first molars, 
putting the bands well over the crowns, with the tubes aligned correctly, 
and the screws of the clamp bands lying close to the lingual surfaces of 
the adjoining teeth, and the bands finally clamped and burnished to 
complete adaptation. Plain expansion arches were now carefully 
shaped to conform approximately to the sizes of the dental arches and 
slipped into place, the upper expansion arch aligning a little below 
the gingival margin of the incisors, and the lower expansion arch 
aligned about the middle of the labial surfaces of the lower incisors. 
Points opposite the upper lateral incisors were now indicated on the 
upper expansion arch, the arch removed, and a sheath-hook attached 
at each of the two points indicated by means of a very small piece of 
soft solder, the arch carried to a very delicate flame and the temperature 



840 ORTHODONTIA 

slowly raised to the fusing point of the solder, jeweller's soft soldering 
fluid being used as a flux. When gold instead of nickel silver is used 
for the arches this form of sheath-hook is not used, but hooks, also of 
gold, are soldered directly to the arch with 22 k gold solder. Soft solder 
must not be used on gold nor hard solder on nickel silver arches. 

The sheath hooks being attached to the arch, it is again inserted in 
the tubes of the clamp bands, with the friction sleeves of the nuts care- 
fully adjusted in the extension flange of the anchor tubes. Much care 
must be exercised in adjusting the bands and the arches so that the 
beautiful fit of the extension flange of the nut with the friction sleeve of 
the tube of the clamp band will not be injured. 

As lateral force on the upper molars was not required in this case, they 
being in their proper lateral as well as mesio-distal positions, little or no 
outward spring was given to the expansion arches. Great care was 
exercised to bend the upper expansion arch so that it would lie close to 
the teeth, yet not touch any of them, and in this way avoid interference 
with the upper lip and inconvenience to the patient, as well as making 
the appliance less unsightly. 

All having been properly adjusted, one of the delicate rubber ligatures 
was caught over the distal end of the sheath of the anchor tubes on the 
lower molars on each side, stretched forward and engaged with the 
sheath-hooks on the upper expansion arch, as shown in Fig. 806, at 
once exerting gentle but constant force distally on the upper molars and 
mesially on the lower molars, premolars, and canines. 

The appliance was now carefully inspected, to be certain that no sharp 
corners should abrade the tissues, and especially that the threaded ends 
of the arches did not protrude distally through the tubes, these ends 
having been cut off and polished when the arches were fitted. Any 
exposed portion of the threads, either on the clamp bands or expansion 
arches, were carefully gone over with a burnisher. The patient was 
directed to keep the mouth closed as much of the time as possible, that 
the force exerted by the rubber ligatures should come at the most 
favorable angle for accomplishing the movement. The patient was then 
given a half dozen of the rubber ligatures and instructed as to how to 
apply them, in case of accident to those already in position, and was 
then dismissed for one week. 

In order that the patient might be caused as little pain and incon- 
venience as possible, both in the fitting and adjusting of the appliances 
and in becoming accustomed to wearing them, a number of short sittings, 
extending over a period of at least two weeks, were employed, never putting 
on more than one band or one arch at a time, or more than one rubber 
ligature on a side, and that of the most delicate tension. Later two, 
or even three, ligatures may be worn on each side with little or no incon- 
venience. Thus by avoiding pain and minimizing the inconvenience 
to the patient in the beginning, success in treatment is made more certain. 



TREATMENT 841 

At the end of a week the patient returned, and it was found that the 
lower teeth had tipped slightly forward, as evinced by the anterior part 
of the expansion arch having moved perceptibly downward toward the 
gingiva. The upper molars had also moved slightly distally, as evinced 
by the expansion arch resting in contact with the labial surface of the 
incisors, as well as moving downward toward their cutting edges to a 
noticeable degree on account of the upper molars having tipped distally. 
The nuts in front of the anchor tubes on the upper molars were now 
tightened by giving them one and one-half revolutions. Both expansion 
arches were then removed and the upper one given a very slight upward 
bend just anterior to the nuts, so that it would align correctly. The 
arch must never be bent but very slightly. It is better to secure align- 
ment by readjusting the anchor bands, or even by changing the angle 
of the anchor tubes by resoldering, although the latter is rarely necessary. 

The teeth and arches were then thoroughly cleansed, the latter slipped 
back into place, fresh rubber ligatures adjusted, and the patient instructed 
and encouraged in the proper cleansing of the teeth and dismissed for 
another week, when the nuts on the upper expansion arch were again 
tightened to avoid any pressure on the anterior teeth and to continue 
to concentrate it all on the molars. 

This treatment was continued until the upper and lower molars 
were in complete normal mesio-distal relations. Indeed, the movement 
was continued until the molars were carried a little beyond their normal 
relations, to allow for the unavoidable slight recurrent movement of 
these teeth during retention. 

The upper arch and anchor bands were then removed and the teeth 
thoroughly cleansed. X bands were adjusted to the second premolars, 
the nuts turned well forward on the expansion arch, the tubes aligned 
properly, and the same expansion arch again inserted, with the nuts 
again so adjusted with the tubes on the X bands as to prevent any pressure 
on the anterior teeth. Then force from the intermaxillary rubber liga- 
tures was again applied. To insure the distal movement of the first 
premolars at the same time, they were ligated to the second premolars. 
In about two weeks the first and second upper premolars on both sides 
had been moved sufficiently distally. The canines had also been moved 
somewhat distally through their relations with the tissues of the alveolar 
process and peridental membrane. 

The nuts on the upper expansion arch were then turned well back, to 
release the force distally on the molars and premolars, and to allow all 
the force now to be received by the upper incisors and canines. About 
three weeks was required to accomplish their necessary distal move- 
ment. 

As the same amount of force had been received on the lower as on the 
upper teeth, the extent of the movement of each was about the same, and 
all were now in normal occlusion. 



842 



ORTHODONTIA 



There was found to be some slight malalignment of the lower incisors 
at this time, which was corrected by means of the expansion arch 



Fig. 905 




already in position, plain spurred bands, and wire ligatures, the same 
as if the case had belonged to Class I. 

The teeth were retained temporarily in their new relations by the appli- 
ances already in position, using only the most delicate force from a 
single rubber ligature on each side and stretching this only one-half 

Fig. 906 




the distance from the tube to the hook, the remaining distance being 
pieced out by a strand of floss silk. 



TREATMENT 



843 



After about three weeks of temporary retention the appliances were 
all removed, the teeth again thoroughly cleansed, impressions taken, and 
models of the teeth made, which are shown in Figs. 905 and 906. 

The retention of the molars was effected by adjusting a No. 2 clamp 
band to each of the molars, the bands fitted with planes and spurs as 
described for the retention of Class II cases in the section on Retention. 

The upper incisors were retained by means of the lingual arch shown 
in Fig. 857, its ends being soldered to the ends of the screws of the clamp 
hands, and the incisors held in proper relation with the arch by brass 
wire ligatures, as described in the section on Retention for cases belonging 
to this class. 

Fig. 907 







1 ' $mfem*. 




nfl T : - 




^KS^.*"~:->\^s!^fKjO 













The lower incisors were retained by plain bands of precious metal 
on the canines, connected lingually by a section of wire, G, as in Fig. 846. 

A second profile photograph of the patient was now taken, shown in 
Fig. 907, and although there is much improvement in the facial lines, 
complete normal contour of the face is still lacking, as is easily under- 
stood when it is remembered that we have corrected the occlusion of the 
teeth only. There still remains the underdeveloped and malformed 
mandible. And again, the muscles had been abnormal in development 
and function, and many months must elapse before they will become 
harmonious with the teeth in their new relations. Indeed, the relations 
of the muscles cannot be entirely normal until the mandible has under- 
gone much modification in growth and development. But as the forces 
through occlusion have been changed from the abnormal to the normal, 
as well as those of the muscles of tongue and lips, the normal in the 
growth has been made possible, and nature is stimulated to complete 



844 



ORTHODONTIA 



the dental apparatus normally, or in accordance with her original design 
of the type of this child. And that nature will do so in these cases 
and has done so in this case is shown by the picture of the patient 
three years later, in Fig. 908, and it is plain to be seen that the mandi- 
ble has developed to normal proportions, with correspondingly gratifying 
results in the balance of the face. 

This case also has an historical interest, for it is the first case of the 
kind where the history was carefully followed and reported in proof 
of the subsequent development of the mandible. 



Fig. 908 




In establishing the normal mesio-distal relations of the teeth in this case, 
and in all similar cases, the question which would naturally be asked is, 
Why was it necessary to move the molars and premolars of the upper 
arch distally if they were already, especially the first upper molars, in 
their normal mesio-distal positions and relations with the skull ? The 
answer is very simple, namely, that we might the more easily and quickly 
and safely establish the normal in relation of the inclined occlusal planes 
of the teeth, and the better stimulate the normal in the growth of bone. 
Another reason is that if all of the movement had been confined to the 
lower teeth, they would have been tipped to an unsafe angle of inclina- 
tion, but by striking a balance between the teeth of the two arches this 
is avoided. 



TREATMENT 



845 



Of course, in proportion as the upper teeth are moved distally to the 
true line of occlusion, the effect is to disturb the balance of the face so 
far as the upper dental arch is concerned, and this is often seen in these 
cases after following this plan of treatment; but it must be remembered 
that the movement of the upper teeth distally and the consequent dis- 
turbance of balance of the facial lines is but temporary. The changes 
in development subsequent to tooth movement must and do gradually 
carry the upper teeth forward again, and thus through the influence of 
the inclined planes constantly stimulated to greater activity and better 
final development of the mandible, for it cannot be too often repeated that 
intelligent efforts in orthodontia can never be more than to assist nature 
in the normal building of the denture according to the type. 



Fig. 909 




In the treatment of these cases, if there is pronounced arrest in the 
development of the mandible, it may be found that the lower teeth already 
incline forward to such an extent that to tip them still farther forward, 
equal to one-half of their distal relations with the upper teeth, as was 
done in the treatment of the case last described, would result in placing 
them at such an unsafe angle of inclination as to possibly interfere with 
the subsequent development of the alveolar process. Such a case is 
shown in Fig. 909. It is then advisable that the movement shall be 
greatest in the upper teeth, and to prevent the lower teeth from moving 
too far forward they must be arrested in this movement at the proper 
time. This is easily accomplished by enlisting stationary anchorage 
between the lower teeth and the lower expansion arch by so placing the 
clamp-bands on the lower molars that the tubes will cause the expansion 
arch to line well down below the gingiva in front, then by springing it 
up and lacing it to the lower incisors by means of wire ligatures, an 
upward and backward pry will be given to the molars by the elasticity 
of the arch, which will prevent further tipping and mesial movement of 



846 



ORTHODONTIA 



the lower teeth, and all of the movement will be given to the upper teeth. 
In like manner the movement of the upper teeth may be arrested when 
this is desired. 

Fig. 910 




Fig. 910 shows the upper arch of this case at the completion of the 
distal movement of the molars and premolars, or at the time the force 
was released from the molars, by turning the nuts forward and trans- 
ferred to the upper incisors. It is in such cases as this that auxiliary 



Fig. 911 




force from occipital anchorage by means of the headgear and traction 
bar may with advantage be used to assist the intermaxillary ligatures in 
carrying the upper teeth distally, yet this necessity would be very rare, 
provided the movements of the teeth and the intermaxillary anchorage 



TREATMENT 



847 



were carefully watched and intelligently managed. The completed case 
is shown in Figs. 911 and 912. 

Figs. 913 and 914 show the occlusion of the teeth in a well-defined 
case belonging to this division of a child, aged less than four years. 



Fig. 912 




It will be seen that all the lower teeth are in distal occlusion and all of 
the forces wrongly directed, and that the malocclusion must be con- 
tinuously progressive so long as these conditions are permitted to exist. 
Notwithstanding the complexity of the malocclusion and the extreme 
youth of the patient the treatment was easily and successfully performed 



Fig. 913 




by the plan described for the treatment of the case shown in Figs. 902 
and 903, and Figs. 915 and 916 show the splendid results in the estab- 
lishment of normal occlusion. 

By comparing Fig. 917 with Fig. 918 it will also be noted how marvel- 



848 



ORTHODONTIA 



Fig. 914 




Fig. 915 




Fig. 916 




TREATMENT 
Fig. 917 



849 




Fig. 91] 




54 



850 ORTHODONTIA 

lous are the changes in the facial lines of this child as a result of this 
treatment. 1 

As the result of intelligent treatment, nature is now permitted to pro- 
gress normally in her work of building the denture, and normally erupting 
and locking the first permanent molars, and the prospects of the ideally 
normal result, as compared with the possible result in cases that have 
been allowed to progress until "all of the teeth (permanent) have 
erupted/' ought strongly to impress all thoughtful persons with the 
gravity of the error of delay. 

Formerly two other methods were employed in the treatment of 
cases belonging to this division of this class. The one almost universally 
followed was to extract the first upper premolars and carry the incisors 
and canines distally by means of occipital force to close the spaces. 
By this method the patching up of one deformity by creating another 
often left the malocclusion worse than at the beginning of treatment, 
often added to the deformity of the face, and made further improvement 
and development hopelessly impossible. The method is so crude, illogical, 
and unscientific from every standpoint that it has been completely 
abandoned by all true orthodontists. 

The other plan formerly employed was far more ideal. It was given 
us by that talented man, Dr. Norman W. Kingsley, and was known as 
"jumping the bite." It consisted in the patient's moving the mandible 
forward voluntarily until the teeth were in normal mesio-distal relations, 
the width and form of the upper dental arch having been so modified 
by previous corrective measures as to make this possible. The mandible 
was then forced to always close in this forward position by means of 
"bite plates" of various forms, until finally it became so modified in 
form and in relation to the temporomaxillary articulation that it would 
no longer move distally, as before. Notwithstanding that the result in 
occlusion and facial balance was very ideal, the difficulty of keeping 
the mandible in the forward position was so great as to cause some to 
doubt its even being a possibility. Yet that it was accomplished in some 
favorable cases after most prolonged and difficult retention is well 
known. In reality we now accomplish in a far quicker and easier manner 
the same ideal results by means of the intermaxillary force as previously 
described. 

As previously stated there were formerly much in vogue two other 
plans for establishing harmony in the sizes of the dental arches in 
cases belonging to this division of this class. The first, and one which 
has been longest practised, necessitated the sacrifice of two upper pre- 
molars, usually the first, followed by the retraction of the canines and 
incisors, in order to harmonize the sizes of the dental arches, and many 

1 This patient was treated in 1904 by Dr. Guilhermena P. Mendell, of Minne- 
apolis. When first reported it was the youngest case on record in which anything 
like such extensive malocclusion of the deciduous teeth had been corrected. 



TREATMENT 



851 



are the devices which have been employed for this purpose. Some of 
them are extremely crude and defective, especially in the principles of 
anchorage, usually relying upon the stability of the first molars for 
overcoming the resistance of the teeth to be moved, the result in nearly 
every instance being the displacement mesially of the anchor teeth, 
usually more than the anterior teeth were moved distally. 




E.H.A 



Fir,. 920 



Other devices depended on a combination of molar and occipital 
anchorage, with better results. The writer's appliances for accomplish- 
ing the retraction of the incisors and canines are shown in Figs. 775 
and 919. It will be seen that stationary anchorage of the molars is 
combined with occipital anchorage, making use of the 
traction-screws, as in Fig. 801, in combination with 
the arch B, the distal ends of the arch being inserted 
in short sheaths attached to the long sheaths of the 
traction screw. The anterior part of the arch B is 
kept in contact with the labial surfaces of the incisors 
(upper) by being made to rest in notches formed in 
the united ends of plain bands on these teeth, made 
from the band material F, as shown in C, Fig. 920. 

Force derived from the headgear through heavy 
elastic bands is transmitted to the ball-and-socket 
joint between the traction bar and the arch B, to the centre of the arch 
B. Additional force from intermaxillary anchorage may also be enlisted 
by use of the rubber ligatures made to engage sheath-hooks on the arch 
B and the anchor-bands on the lower molars, as already described in the 
first plan of treatment. Although the device here shown is unques- 
tionably the most simple and efficient for carrying out this plan of 




E..H. A. 



852 



ORTHODONTIA 



treatment, yet the principle of treatment itself is obviously wrong and 
ought rarely, if ever, to be employed, for at best it is only palliative, 



Fig. 921 




Fig. 922 




creating one deformity to patch up another. There is always a strained 
and unnatural look given to the mouth, following this plan of treatment. 



TREATMENT 853 

The writer has yet to see a single instance where the facial lines have 
been much improved over their former condition, and in some instances 
they had been made radically worse after treatment by this method. 
Fig. 742 shows the facial lines of one patient after such treatment. 

This plan of treatment was, of course, excusable before the intro- 
duction of the Baker anchorage; in fact, it was then the only one that 
might safely be relied upon; but with the progressive orthodontist it can 
no longer be in favor, and we believe it is destined to become obsolete. 

Another plan of treatment, introduced by Dr. Norman W. Kingsley, 
consisted in what he termed "jumping the bite," or shifting the position 
of the mandible and lower teeth from distal to normal occlusion (which 
anyone with distal occlusion can do voluntarily), and holding the jaw 
in this position by some form of mechanical device until either the jaw 
or temporomaxillary articulation, or both, had supposedly been modified 
to be in harmony with the teeth in their corrected occlusion or normal 
relations, when, it was supposed, there would be no recurrence of the 
former condition. 

Fio. 923 




In order to establish harmony in the occlusal inclined planes in this 
manner it was, of course, necessary to first place the teeth of the upper 
arch in harmony with their normal line of occlusion; that is, widening 
this arch somewhat in the region of the canines and premolars, and 
moving lingually the protruding incisors, which was done by various 
forms of mechanical devices. 

This plan of treatment has occasioned much controversy, its practi- 
cability being doubted by many and stoutly defended by others. The 
great advantage of the method, were it practicable, over the one last 
described must be apparent to all, for, in addition to the first requisite 
in the treatment of malocclusion, the complete restoration to normal 
occlusion, it made possible the restoration of the chin and lower jaw to 



854 



ORTHODONTIA 



harmony of balance with the rest of the face. No wonder it should 
have strong advocates, especially by those of Dr. Kingsley's type, who 



Fig. 924 




set much score by the artistic balance of the face. But, as we shall see, 
one important phase of the conditions contingent on this plan of treat- 
ment has been overlooked by the advocates of this plan. The follow- 
ing case, which was treated after this plan, will illustrate this. The case 



Fig. 925 




was that of a boy aged nine years. It will be seen from the mal- 
occlusion (Fig. 921) and the facial lines (Fig. 922) that the case is one 



TREATMENT 



855 



typical of this division of this class. The first permanent molars on 
both sides had erupted and locked in complete distal occlusion, with 
the usual narrowed upper arch and protruding upper incisors. 



Fig. 926 




Fig. 923 shows the occlusal aspect of the upper arch, and the dotted 
line in the engraving indicates the relation of the lower teeth. 



Fig. 927 




The teeth of the upper arch were moved into correct relation with 
their proper line of occlusion, which resulted in the shortening and 



856 ORTHODONTIA 

widening of the arch. The lower jaw could then be moved forward, 
and, upon closing, the teeth were in normal occlusion, as shown in Fig. 
924. Closure in this position was compelled by the devices shown in the 
engraving and already described in retention. 

This plan of retention was continued for a period of two years, being 
shifted from one side to the other, and occasionally employed on both 
sides at the same time. It will be noted by studying the profile of the 
young man's face (Fig. 925) that the lower jaw has been carried well for- 
ward, and that it is now in excellent harmony with the rest of the face, 
in marked contrast with the weak, receding chin shown in Fig. 922. 

Gradually retention was discontinued, and the deciduous molars were 
lost and replaced by their successors, each locking normally with its 
antagonist. Some two years after all devices for mechanical retention 
had been removed, a study of the occlusion of the teeth, as shown in the 
correctly made models (Fig. 926), revealed normal occlusion. The writer 
felt positive he had succeeded in "jumping the bite." Meantime other 
cases had been carried on with equally good results. But an important 
change had been taking place in this case, probably from the very begin- 
ning of retention, and yet unnoticed. This change was discovered by 
a comparison of the profile of the young man at the age of fifteen (Fig. 
927) with the photograph of his profile taken at the time of completion of 
treatment (Fig. 925). It clearly showed that instead of the temporo- 
maxillary articulation having been permanently modified to be in har- 
mony with the new position of the mandible, that in reality the mandible 
had gradually worked back into its old relations, and that, too, without 
displacing the normal relations of the inclined occlusal planes, the expla- 
nation of this being that the crowns of the upper teeth had to a certain 
extent been tipped distally and the crowns of the lower teeth more or less 
mesially; or, in other words, there had occurred in this two-year period 
of retention what we now aim to accomplish and do accomplish in a very 
few weeks with the Baker anchorage. 

Inspection of other cases showed like results. In one instance in which 
retention had been continuous on one side the same result had occurred, 
as shown in Fig. 926, but on the other side, the retaining device having 
been lost and not replaced, as the mandible regained its former relations, 
the teeth also drifted back into their original positions of distal occlusion. 

Class II. — Division 1, Subdivision. — Practically the same conditions 
are met in cases belonging to the subdivision of Division 1, Class II, as 
are found in Division 1, just described, the only difference being that 
on one side only have the teeth locked abnormally, or the lower in distal 
occlusion, the teeth on the other side being locked in normal occlusion. 

There is the same narrowing, only less in degree, of the upper arch, 
with incisors protruding, in many instances quite as much as in the full 
division, and with facial lines marred just in proportion to the extent of 
the malocclusion. 



TREATMENT 857 

The treatment indicated is the same as in all cases of malocclusion, 
namely, the establishment of the normal relations between the inclined 
occlusal planes. In this class of cases this is brought about in pre- 
cisely the same manner, and with the same combination of appliances 
used in the same way, as in cases belonging to the full division, or in 
distal occlusion on both sides, except that the sheath-hook and rubber 
ligatures for shifting the upper teeth distally and the lower teeth mesially 
are used only on the side of the distal occlusion, although sometimes, 
in order to maintain the proper balance of the appliance, only gentle 
intermaxillary force becomes necessary as well on the normal side. 

Of course, if there is required, and there often is, any individual tooth 
movement in either of the dental arches, they are effected at the same 
time as the distal shifting of the upper teeth and the mesial tipping of 
the lower by means of spurred bands and wire ligatures, as described 
in the treatment of cases belonging to Class I. 

The teeth that have been moved are retained in the same way as 
described for cases belonging to Division 1, Class II. 



Fig. 928 




Class II. — Division 2. — It will be remembered that in cases of mal- 
occlusion belonging to this division of Class II, as in those of Division 1, 
the teeth of the lower arch are in distal occlusion in both its lateral halves. 
The upper arch, unlike that in cases of Division 1, which is abnormally 
long and narrow, is shortened, with incisors bunched and overlapping, 
as in Fig. 928, to approximately harmonize in size with the anterior part 
of the lower arch. Unlike the conditions of Division 1, the lower incisors 
are not elevated in their sockets, owing, probably, to their greater use, 
and there is normal respiration and lip function, with a far more normal 
vault and width of arch, but the result of distal occlusion and recession 
of the jaw and chin greatly mars the facial lines, as shown in the face 
in Fig. 736. 

The logical plan of treatment in this, as in all cases of all classes, 
and one that is thoroughly practical and not difficult of accomplish- 



858 ORTHODONTIA 

ment, especially if treatment be begun early and intelligently managed, 
is the establishment of normal occlusion of the teeth. 

As cases belonging to this division require the same movements of 
the molars, premolars, and canines as do cases belonging to Division 1 
of this class, they are accomplished in exactly the same way and with 
the same combination of appliances. 

But the upper incisors, being more or less retruded, bunched and over- 
lapping, their torsal and labial movements are required, and these are 
effected at the same time the upper molars and premolars are moved 
distally, by means of plain bands, spurs, and ligatures engaging the 
expansion arch, precisely as would be done in cases belonging to Class I 
(see Fig. 769), the mesial movements of these teeth reciprocating force 
to the molars and making more easy the movement of both. 




If the positions of the lower incisors require corrections, this is accom- 
plished by bands, spurs, and wire ligatures in connection with the lower 
expansion arch, at the same time the mesial movement of the lower 
molars, premolars, and canines is effected. 

Both upper and lower incisors are retained in the same manner as 
for the same teeth in Class I, similar tooth movements having been 
performed, and the molars, premolars, and canines as previously de- 
scribed for the retention of these teeth in Division 1, Class II. 

Although these cases are apparently more complicated than those of 
the first division, usually they are more easily treated. 

Again, as the patients are normal breathers and keep the mouth 
closed the requisite amount of time, the time of retention of the 
molars by mechanical devices is shorter, as the normal locking of 
the cusps — nature's most important retaining device — thus becomes 
more effective. 

Fig. 929 shows the case corrected and at the time of adjustment of 
the retaining devices, and the face in Fig. 737 shows the result of 
treatment on the facial lines 



TREATMENT 



859 



The case here shown is one purposely selected as being not only 
typical, but also of unusual difficulties, owing to the large size and 
density of the jaws, and the full complement of unusually large teeth, 
all of which were in malocclusion and required to be moved in order 





Fig. 930 






i» A«-<1 


""A 




cM 


.1 AcH* 









to carry out this plan of treatment, yet the mesial movements of all the 
lower teeth and the opposite movement of the upper molars, premolars, 
and canines, together with the necessary individual movements of the 
incisors and canines, were effected simultaneously and in about three 
months' time. 



Fig. 931 




Of course, the golden time for the treatment of this case was at, or 
soon after, the time of the eruption of the first molars, and the difficul- 
ties of treatment have gradually increased with the advance of years. 
It is quite probable that all that would have been necessary at that 



860 



ORTHODONTIA 



time would have been simply the directing into normal relations of the 
first molar teeth. 

Fig. 930 shows the malocclusion of another case from both right 
and left sides, this patient being much younger, but the treatment being 
after the same plan. 

Fig. 931 shows the facial lines of the patient before treatment and 
how greatly they were marred by the pronounced malocclusion. 

Fig. 932 shows the case at the time of the adjustment of the retain- 
ing devices, and it will be noticed how short the bite is in the incisive 
region, and this gives us an opportunity to point out the importance of 
establishing the normal length of overbite, and while this condition mav 
be met in the treatment of any case of any class, it is, as Dr. Kirk has well 
said, "of quite as much importance that the proper length of bite be 
established as it is that any other phase of malocclusion be corrected." 



Fig. 932 




Where the overbite may in some instances be due to the supra-eruption 
of the incisors, it will in most instances be found to be due to the infra- 
eruption of the first molars, and usually the lower ones. 

Naturally the elevation and retention of the lower first molars by 
mechanical means would seem to be the correct solution of this problem, 
and while their elevation is not difficult to accomplish, yet the writer 
has never been successful in maintaining the teeth in this position, even 
though they had been mechanically retained for many months, for upon 
the removal of their mechanical support they would graduallv settle 
back into their original positions and the overbite become as before. 
The reason for this was puzzling, jet when we remember the great 
force received upon these teeth from occlusion and the great disturbance 
in the attachment of the fibers in the peridental membrane, and especially 
the immense number of suspensory fibers which have been recurved 
upon themselves in the elevation of these teeth, we can understand 
how long a period of time must be required before there can be a recon- 



TREATMENT 



861 



structed, normally functionating membrane and osseous attachments, 
especially in patients nearing maturity. So the plan that the writer 
has found to be most satisfactory is one that has long been in use, namely, 
to separate the bite by a yulcanite plate, thickened in front and coyering 
the yault of the arch, with depressions in the plate for the reception of 
the lower incisors so that the full thrust of the jaw may be receiyed upon 
these teeth instead of upon the molars. The plate is prevented from being 
forced upward in front, and from being loosened in the rear, by hooks 
firmly embedded in the plate and made to engage the cutting edges of 
the upper incisors. When properly adjusted this plate should relieve 
all strain from the opposing first molars which are separated at least 
three thirty-seconds of an inch. If constantly worn for from six months 



Fig. 933 



Fig. 934 




to a year the molars will have become lengthened and the proper length 
of bite established. The result of this method of treatment is shown in 
the fine balance that has been given to the facial lines (Figs. 933 and 934) 
and in the improvement in the occlusion (Figs. 935 and 936). 

It may be well to note that in nearly all cases belonging to Class 
II there is more or less of an abnormal overbite, sometimes most pro- 
nounced, but it is gratifying to note that this will in most instances 
disappear as the crowns of the teeth are tipped into their normal posi- 
tions, or their normal angles of inclination established. 

While numerous simpler cases belonging to this dixision might be 
reported here, this seems unnecessary, as the stories they might tell in 
occlusion and art and in the methods of accomplishing the various 



862 



ORTHODONTIA 



tooth movements are embraced in the cases already reported, and if these 
be understood the treatment of simple cases should offer no difficult 
problems. 



Fig. 935 




Fig. 936 




Class II. — Division 2, Subdivision. — In cases belonging to this sub- 
division the conditions and indications for treatment on the abnormal 
side are similar to those in Division 2, Class II, just described, the 
differences being, like those of the subdivision of Division 1, Class II, 
that one of the lateral halves of the dental arches only is in distal occlusion, 
the lower first molar on this side failing to lock normally; but, as it 



TREAT ME XT 



863 



erupted, was shifted into distal occlusion, necessitating the abnormal 
locking of each succeeding tooth that erupted on that side, until we 
have inharmony in the sizes of the arches, the upper being larger to 
the extent of one premolar tooth, and the compensation being in the 
overlapping of the upper incisors and canines, as shown in the typical 



case. Fig. 93, . 



Fig. 937 




The treatment clearly indicated was the correction of the malposi- 
tion of each tooth in each arch; at the same time the relations of the 
dental arches were made to harmonize by the movement mesially of the 
lower teeth on the abnormal side one-half the width of a premolar, while 
the upper incisors, premolars, and canine- were shifted distally to the 
same extent by the use of the expansion arches. I) bands, etc.. in con- 
nection with the intermaxillary anchorage, all as described in the treat- 





Fig. 18 






Ace It — 
J Ace ir 








mm 






( 4 < < 


■■ra 







ment of cases belonging to Divisions 1 and 2 of this class. The result 
is shown in Fig. 93S. 

Fig. 939 shows the facial lines before treatment, and Fig. 940 shows 
how greatly they have been improved as a result of correcting the mal- 
occlusion. The weak appearance of the lower part of the face, through 



864 



ORTHODONTIA 



its recession, has been strengthened and almost perfect balance of the 
mouth with the rest of the features has been established. 

A former plan of treatment by the writer for these cases is shown in 
Fig. 821, in which harmony in the sizes of the arches was established 
by extracting the first upper premolar on the abnormal side and retract- 
ing the canine, and at the same time the incisors and canines were 
rotated into correct alignment. 



Fig. 939 



Fig. 940 




The combination of the traction-screw and expansion arch, wire 
ligatures, etc., is well shown, and, indeed, this is one of the most 
thoroughly efficient devices for performing tooth movements that is any- 
where found in the history of orthodontia, as each part 
most perfectly braces and assists reciprocally the other 
parts of the device in effecting the various tooth move- 
ments, and it was the occasion of much pride with 
the writer. But by this plan of treatment mutilation 
was necessary, with all its attendant evils in occlusion, 
tongue restriction, and facial deformity, and since nor- 
mal occlusion is now so easily established by intermax- 
illary force, as previously described, its use is rarely, 
if ever, required. 

Class III. — In the treatment of cases belonging to Class 

III, the degree of our success, more than in any other 

orthodontic work, depends on beginning treatment early. 

This form of malocclusion usually begins at about the time of the. 

eruption of the first permanent molars, although it may begin earlier, and, 

as the writer first pointed out, it is always associated in its beginnings 

with enlarged tonsils, the habit of protruding the mandible probably in 




E. H. A. 



TREATMENT 865 

some way affording some relief in breathing, which habit, it seems reason- 
able to the writer to believe, is a potent factor in the locking of the first 
permanent molars, as they erupt, into mesial malocclusion. And when 
once the mesio-buccal cusp of the upper first molar begins to engage the 
distal incline of the disto-buccal cusp of the lower first molar, the result 

Fig. 941 




mechanically is to force the mandible forward on each closure of the jaws. 
This in time forces the deciduous teeth into malocclusion, as well as each 
succeeding permanent tooth as it erupts, thereby enlisting the other 
inclined planes to act out of harmony with nature's intended plan, and 
to assist in accelerating the forward movement of the mandible. Not 
only this, but the bone is thus stimulated to develop abnormally, which 

Fiu. 942 




is probably furthered to no small extent by the added stimulus of the 
muscles in their abnormal relations with it. 

So, after the lower first molars are locked in mesial occlusion and 
the forces perverted, the progress must be and is rapid, only a few 
years being necessary to develop by far the worst type of deformity 
55 



866 



ORTHODONTIA 



the orthodontist is called upon to treat; and when the case has pro- 
gressed until the age of perhaps sixteen, or after the jaws have become 
developed in accordance with the malpositions of the teeth, all excepting 
the third molars having erupted by this time, the case has usually passed 
beyond the boundaries of simple malocclusion and into that realm of 
marked complications, namely, bone deformities, with little possibility, 
with our present knowledge of the subject, of affording much relief by 
orthodontic measures. 

If these cases could receive prompt attention at the important period 
of the eruption of the first molars, the throats properly treated, and the 
first molars mechanically assisted into normal relations, and there com- 
pelled to remain by delicate yet efficient retention for a few months, 
these unsightly deformities would never develop. 

Fig. 943 




There may be, and doubtless are, other factors that enter into the 
production of these as yet but imperfectly understood deformities; but 
we are convinced that they are of minor importance to those we have 
mentioned. 

The time-honored shifting of these conditions on to heredity and 
supposed degenerate tendencies no longer satisfies or carries much weight. 

Figs. 941 and 942 show the malocclusion in the case of a child, aged 
six years, who was, and had been for some time, a sufferer from greatly 
enlarged faucial tonsils. The first permanent molars are erupting, and 
the lower ones, in taking their positions, will soon become fully locked 
in mesial occlusion. This is a fair example of the beginning of all these 



cases. 



TREATMENT 



so; 



The deciduous teeth are rapidly becoming harmonized to the abnor- 
mal occlusion, the lower incisors now closing mesially to the upper 
incisors. Thus the tendency is clearly indicated and its effects shown 
on the facial lines (Fig. 943), and this condition has developed rapidly, 
the contour of the baby face being thus changed in but a few months. 



Fig. 944 




The treatment was simple and easy. Small D bands were placed 
upon all four deciduous second molars and the plain expansion arches 
(small) were adjusted, as per combination shown in Fig. 812, and force 
exerted by means of the delicate rubber ligatures made to engage the 
sheath-hooks on the lower arch, which were placed well forward, or 



Fig. 945 




opposite the lateral incisors, and the other ends stretched over the distal 
ends of the sheaths of the upper anchor-bands, the result being that in 
a very short time the teeth were shifted into normal relations. 

The case was retained by means of two delicate spurs soldered to 
the lingual surface of delicate bands on the upper deciduous central 



868 



ORTHODONTIA 



incisors, these spurs extending downward and somewhat forward in front 
of the lower centrals, thus compelling the normal closure of the mandible, 



Fig. 946 




and Figs. 944 and 945 show the occlusion at this stage, the lower decid- 
uous laterals meantime having been lost. The pronounced change in 



Fig. 947 




the facial lines as the result of this modified occlusion is shown in 
Fig. 946, 



TREATMENT 



869 



The eruption and locking of the first permanent molars was now com- 
plete, and the deciduous upper incisors, with their retaining bands 
and spurs, were lost through the natural absorption of their roots a few 
weeks later, and, although several years have since elapsed, the occlu- 



Fig. 948 




sion is practically faultless and the facial lines are in excellent balance, 
as shown in Fig. 947. 

Fig. 948 shows the malocclusion in another case of a patient seven 
years older, in which the natural progress of the deformity is clearly 
shown. 

The result in the inharmony of facial lines is shown in Fig. 738. 

Fig. 949 




The treatment clearly indicated was to establish harmony in the sizes 
of the arches and normal relations of the inclined occlusal planes. 
Without the intermaxillary force this would have been impossible, but 
with it the desired changes were effected, and that, too, quite speedily. 



870 



ORTHODONTIA 



The same combination of appliances as that described for* the last 
case was also used in this. The force necessary to shift mesially the 
upper teeth was reciprocated to move distally all of the lower teeth. It 



Fig. 950 




E.H.A. 



Fig. 951 




is quite probable that the mandible was also moved distally somewhat. 
In fact, this is shown in the facial lines after treatment (Fig. 739), but 
the principal change was in the positions of the crowns of the teeth 
after three weeks' treatment, shown in Fig. 949. 



TREATMENT 871 

No effort was made to establish better relations between the pre- 
molars, knowing full well that as these teeth continued their eruption 
they would be forced more and more into their normal relations through 
the influence of their inclined occlusal planes. 

The retention was effected as described in the section on retention 
for cases belonging to Class III. 

Any purely orthodontic treatment in such pronounced cases as that 
shown in Fig. 950 (facial lines in Fig. 951) is a waste of time both of 
patient and operator. The only possible relief would be by performing 
the writer's operation known as "double resection of the jaw," 1 but as 
that comes under the realm of surgery, its consideration does not properly 
belong here. 

Fig. 952 




Even in such cases as that shown in Fig. 952, in which the malocclu- 
sion has never passed beyond simple mesial occlusion, yet at this age of 
the patient (twenty-five years) the jaws and muscles have become fixed 
in their abnormal development, and the result, after many months of 
patient, persistent treatment, will usually be found to be most discour- 
aging and unsatisfactory. They are good cases to avoid. 

We have elsewhere given our views relative to the use of the chin 
retractor and occipital anchorage in connection with the treatment of 
these cases, and how they have practically become superseded by the 
intermaxillary anchorage. The writer no longer finds value in their 
use, although there is the barest" possibility that they may still in some 
instances have use as an auxiliary to the intermaxillary anchorage. 

Class III. — Subdivision. — As cases belonging to the subdivision of 
Class III are in unilateral mesial occlusion, the treatment clearly indi- 
cated, especially in young patients, is after the same plan we have 

1 For the consideration of this operation see the writer's Malocclusion of the 
Teeth, seventh edition. 



872 ORTHODONTIA 

described for the full division, exerting force, however, only on the side 
that is in mesial occlusion. 

In this short treatise the writer has aimed to point out a simple, 
logical system not only of diagnosticating malocclusion, but also its treat- 
ment, from the simplest to the most complex cases — and all from the 
basis of normal occlusion. 

And finally, orthodontia is now one of the well-recognized specialties 
of medicine, and in its practice the possibilities for adding to the health, 
beauty, and happiness of humanity are so great as to make it a most 
inviting field. Yet it must be remembered that the difficulties in the 
practice of orthodontia are such that only those who have an aptitude 
for the work and will study it broadly and thoroughly will ever be 
successful in its practice, but for such a limitless field and prompt 
recognition is waiting. 

Orthodontia should be taught and practised as a distinct specialty, 
for there is no specialty in medicine with more clearly defined boundary 
lines. To the mere smatterer it is a most unpromising and unprofitable 
field of labor, but' to those with an aptitude and liking for the work, who 
by study and patient endeavor master it, orthodontia is for many reasons 
a most ideal specialty, and offers opportunities not now approximated 
by any other in medicine. 

Malocclusion of the teeth is so prevalent, and its intelligent treatment 
followed by benefits so pronounced in the health, happiness, and beauty 
of the patient, that although it is the newest specialty in medicine it is 
destined soon to be recognized as one of the most important. 



CHAPTEE XXII 
DENTO-FACIAL ORTHOPEDIA 

By CALVIN S. CASE, D.D.S., M.D. 
INFLUENCE OF THE TEETH ON THE PHYSIOGNOMY 

In the developmental processes of animal life the teeth have probably 
been more influential than any of the other organs in shaping the bones 
of the head — especially in determining the physical characteristics 
of the physiognomy. The physical shape and structure of the jaws 
conclusively show the influence that the teeth have exerted in different 
species in response to nature's effort to propagate that which would best 
subserve them in the performance of their functions. The importance 
of the teeth, therefore, and their inherent demand upon surrounding 
anatomical structures for proper means of development, sustenance, and 
use, is evidence that they exert, during development, a more or less 
immediate influence in determining the size and shape of the maxillary 
bones, and thus indirectly are extensively influential in characterizing 
the individual shape of the human face. 

Often the position of the anterior teeth and alveolar process is such 
as to impress upon the contiguous features, even in repose, certain con- 
ditions which vary from a slight imperfection in esthetic contour to a 
most distressing facial deformity. Nor are these dento-facial imper- 
fections always wholly due to a malposition of the teeth, so much as to 
a lack of normal symmetry in the size or shape of the maxillary bones 
upon which so large an area of the face is dependent for its contour. 

Causes. — These conditions may have arisen from the direct inherit- 
ance of a parental deformity, or from the inharmonious union of undi- 
luted types. It is equally true that the offspring of inharmonious types 
often results in symmetrical conditions which neither parent possesses. 

Among local causes, or those which operate after birth in the pro- 
duction of facial imperfections, may be mentioned habits, impaired 
dentition, delayed and injudicious extraction of the deciduous teeth, 
and diseases of the nasopharyngeal passages, causing a lack of normal 
development of adjoining bones, often accompanied with mouth breath- 
ing, with its far-reaching effects. 

The influence of the teeth during the time of their eruption (pro- 
ducing on the one hand the excessive pressure of large teeth and con- 
comitant alveolar development, and on the other a lack of pressure from 

(873) 



874 DENTO-FACIAL ORTHOPEDIA 

an irregularity or injudicious extraction) in effecting a change in the 
inherent shape or size of the maxillary bones beyond that which the 
alveolar process is forced to assume to accommodate them, has been a 
question of considerable controversy. 

While it is of common observation that bones are retarded and even 
permanently stunted in their growth development by both natural and 
artificial causes, and thus made to assume a diminished size, I think 
it may be stated as a fact that there is no authentic record of bones 
having been made to grow, in the individual, appreciably larger or 
longer than the normal size, by artificial force. 

By the early removal of the causes of non-development — as in the 
removal of adenoids, which have retarded the development of the 
superior maxillae and other bones — the affected bones may develop to 
their full normal size after the cause is removed, if properly aided by 
artificial stress. 

It is reasonable to assume that artificial force cannot cause the pro- 
duction of that which is commonly seen to be apparently impossible 
by the strongest of the natural physical forces operating during the 
early stages of childhood development and through adolescence. I 
refer to those commonly seen dental protrusions, unimaxillary and 
bimaxillary, which evidently assume this position because the teeth 
are too large for the natural size of the jaws in which they are placed. 
The pressure of erupting teeth, as is the force exerted by all natural 
growth, is far greater than one would imagine who had not carefully 
observed its effects. Why is it then that this great pressure of the erupt- 
ing permanent teeth, crowding their way in between the rami and the 
labial arch does not cause the disto-mesial enlargement of the body of 
the mandible, so as to extend the chin forward somewhat in harmony 
with the protruded position of the teeth? If this were possible we 
would not so frequently see the appearance of receding chins occurring 
with people whose mandibles are in full harmony as regards size, with 
the balance of the features; the effect being purely because of an 
excessive abnormal protrusion of the lower teeth and alveolar process. 

With bimaxillary protrusions the dentures will frequently be found 
in normal occlusion, alignment, and in proper arch width with the pro- 
duction nevertheless of a decided abnormal prominence of the mouth, 
extending over the entire dento-facial area (Fig. 953). 

This is a question of the greatest importance to consider in the con- 
templation of moving the lower dentures of young children forward 
with the intermaxillary force to place them in normal occlusion with 
protruded uppers — an operation that is questionably advocated and 
unfortunately extensively and indiscriminately practised today. 

If one could be sure, at these early stages, that the lower dentures 
were destined to be retruded in relation to the mandible and that this 
forward movement would not ultimately result in a receding chin effect 



INFLUENCE OF THE TEETH ON THE PHYSIOGNOMY 875 

it would be excusable and demanded. It unfortunately happens in a 
large proportion of these cases that the disto-mesial malocclusion of 




the buccal teeth is due solely to an inherent protrusion of the upper 
dentures, which in the operation of adjusting the occlusion to normal 
with the intermaxillary force, the uppers are retruded only one-third 
or at most one-half as much as thev should be to correct the facial 



Fig. 954 




deformities; the whole resulting in bimaxillary protrusions stamped 
upon many faces for life whose features might have been handsome 



876 



DENTO-FACIAL ORTHOPEDIA 



Fig. 955 



had the upper first or second premolars been extracted and the labial 
teeth fully retruded, with no movement of the lower dentures and upper 

buccal teeth, except that required to adjust 
the closure to a perfect interdigitating 
occlusion (Fig. 954). 

Irregularities of the teeth caused by dis- 
eases of the naso-maxillary sinuses and, 
secondarily, by a lack of development of 
the maxillary bones, pertains directly to 
the upper jaw, although the lower teeth 
may also be forced into malposition 
through the influences of imperfect oc- 
clusion, and even the mandible itself 
may be changed in shape by the concomi- 
tant mouth breathing, causing an open- 
bite malocclusion. 
With the primary cause of these conditions removed at an early age, 
the retarded development of the superior maxilla? may be made to assume 





its normal size and shape. A peculiarly fortunate possibility arises 
from the fact that a retruded incisive portion of the maxilla? may be 



INFLUENCE OF THE TEETH ON THE PHYSIOGNOMY 877 

forced forward to a normal position with a bodily protruding movement of 
the incisor teeth. It would seem that it was only the alveolar ridge that 
moved, were it not for the fact that in those cases where the end of the 
nose is carried backward through a lack of forward growth development 
of the incisive process it is commonly carried forward and straightened 



Fig. 957 




in this movement (see Figs. 968, 973, and 978). When it is remembered 
that the end of the nose is supported by the cartilaginous septum 
attachment to the nasal spine of the superior maxillary bones, it will 
be seen that the incisive portion of the maxillae proper must move to 
carry the end of the nose forward as it frequently does. 

The bodily forward movement of the labial teeth is now an operation 
that is quite as easily accomplished with the proper apparatus as any 



Fig. 959 



Fig. 9150 





of the other extensive movements of regulating. For patients not older 
than twelve or fourteen years, the entire incisive alveolar ridge is com- 
monly carried forward with the teeth. 

This is well shown in the accompanying illustrations made from the 
models of a face when presented at twelve years of age, showing a decided 
retrusion of the upper incisor teeth involving the entire incisive alveolar 



878 DENTO-FACIAL ORTHOPEDIA 

ridge. Other parts of the jaws and teeth were in normal size, relation, 
and occlusion. 

The illustrations on the left show different views of the case at the 
beginning of the operation, and those on the right after the teeth and 
alveolar ridge had been bodily protruded with the contouring 
apparatus shown in Fig. 961. 

This cut was made from a photograph of the apparatus which the 
patient wore, and which after removal was placed on her dental casts 
as shown. 

In dental orthopedia we possess the great advantage over general 
orthopedia of applying force directly to the bone itself, through the 
medium of the teeth, without the intervention of the soft and sensitive 
tissues. 

Fig. 9G1 



■ s *i 


^^^^ 


. -4 





The teeth embedded in the alveolar process that in turn is firmly 
united to the true bone may be considered, when in the grasp of a regu- 
lating machine, as an integral part of it, firmly and directly attached 
to that part of the bone we desire to move, and capable of exerting 
the quality and direction of force the machine gives to them. 

This force being applied unitedly to a number of teeth standing side 
by side, the surrounding and contiguous bone — which is largely a can- 
cellated structure — is carried bodily in the direction of the force; not 
by the fracture of its substance or to any great extent by a metamor- 
phosis of tissue, but by the bending, condensation, and elongation of its 
cellular structure; the whole adapting itself to a new form, in which 
position the immediate interstitial tension of its particles is soon relieved 
and brought to equilibrium by nature — although it may require to be 
held in that position for- many months before there is an entire relief 
from the inherent tendency to return to the former position. 

Dento-facial Diagnosis. — In contemplating the treatment of a dental 
irregularity a careful study of the physiognomy in different attitudes 



PRINCIPLES OF FACIAL ORTHOPEDIA 



879 



of expression should be made, with the view of determining the relative 
position of teeth and facial contours. The value of a careful preliminary 
facial examination and comparison cannot be overestimated, for it is 
often the only guide to correct treatment. 

For instance, since it has become possible to expand or retract the 
anterior portion of the upper apical zone with the surrounding bone in 
which the moving roots are embedded, we are no longer confined to the 
possibility, and frequent questionable propriety, of permanently moving 
the lower jaw forward or backward to correct a facial deformity which 
pertains exclusively to the upper maxillae and middle features of the 
face. 

PRINCIPLES OP FACIAL ORTHOPEDIA 

The portion of the human face that it is possible to change with a 
dental regulating apparatus may be said to lie between two diverging 

Fig. 962 




A, upper apical zone 

B, upper coronal zone 

C, lower coronal zone 

D, lower apical zone 



lines which arise at a point below the ridge of the nose and curve down- 
ward to inclose the alae and depressions on either side; thence laterally 
to encircle a portion of the cheek, and downward to inclose the entire 
lower lip and labio-mental curve (Fig. 962.) 

Within this ovoidal area the slightest change of muscular movement 
expressive of the emotions will produce an apparently marked effect 
upon the entire physiognomy. The same is true of any physical imper- 
fection of contour, particularly around the mouth. It is here that an 
inherited or acquired lack of symmetry in the size, shape, or position of 
the teeth and jaws produces those marked changes of facial contour which 



880 DENTO-FACIAL ORTHOPEDIA 

characterize the several classes of dento-facial deformities. This area 
may be termed the " changeable area" in contradistinction to the more 
stable features, or "unchangeable area." 

For convenience of ready reference, the features in that portion of 
the changeable area which are bounded laterally by the naso-labial lines 
may be divided into four segments as shown. 

In the preliminary examination of the physiognomy from a purely 
esthetic standpoint with a view of correcting a dento-facial deformity 
or imperfection, by applying force to the teeth, there are certain prom- 
inent features to be especially observed and their relative position care- 
fully noted. These may be divided into two classes: First, those which 
lie in the unchangeable area, as the forehead, bridge of the nose, malar 
prominences, and chin; second, those in the changeable area. 

The four segments in the latter class shown in Fig. 962 are change- 
able in their relations to each other, and also in their individual relation 
to features in the unchangeable area. For instance, it is possible to pro- 
trude or retrude the upper portion of the upper lip with the depressions 
on each side of the nose, the nasal septum, and the end of the nose, 
without changing the lower portion of the upper lip in its relation to 
other parts. The same is true of the other segments — in fact, a retrusion 
of the upper coronal zone and a protrusion of the upper apical zone 
may be accomplished at the same time (see Figs. 971 and 972). 

That part of the cheeks which lies over the premolars and first molars 
will frequently be rounded out to a fuller contour, although the causes 
which operate in this result are not direct as in the changeable area 
proper. The lateral expansion or contraction of the dental arches will 
often change the contour of the cheeks with no effect upon the labial 
area, if the anterior teeth remain unchanged in position. Again, a decided 
retrusion of the anterior teeth and process with no lateral expansion 
of the arch will invariably result in giving to the cheeks a fuller contour, 
by relieving the tension of muscular tissues. The same result will 
often be obtained in closing the characteristic open bite of a mouth- 
breather by grinding the posterior teeth, and also by retracting a prog- 
nathous lower jaw. 

In a study of profiles we frequently observe a lack of perfect har- 
mony in the position of the chin. The lower jaw is apparently protruded 
or retruded, so as to mar the esthetic perfection of the physiognomy, 
and yet were these same faces examined by a trained observer he would 
find in a large proportion the lower jaw in perfect harmony with the 
unchangeable area, and that the appearance of its malposition was an 
effect due wholly to a protrusion or retrusion of the upper jaw and teeth. 
In other words, it is a common error to imagine the chin imperfectly 
posed because it is not in harmonious relations to the other features 
of the changeable area, instead of comparing it, as we should do, to the 
more stable or unchangeable features of the physiognomy. 



k 



UPPER PROTRUSIONS 881 

In examining the physiognomy of a patient, the head should be in 
an upright position, on a line with that of the observer, and the face 
studied from different angles while in repose and in action. 

While looking at the profile in repose the most important thing to 
determine is the relative position of the chin with the forehead, malar 
prominences, and bridge of the nose. If its position is harmonious 
with the unchangeable area and the lower lip is well posed, it indicates 
that the operation of facial contouring should be performed — if any- 
where—upon the upper jaw and teeth. For if the first and second 
segments are abnormally protruded it will cause a chin to appear retruded 
that is perfectly harmonious in its relations to the principal features of 
the face. Again, a retruded or contruded upper arch with a depression 
of those features which are supported by the superior maxilhe will 
cause a perfectly posed lower jaw and chin to appear protruded or prog- 
nathous; as instanced by many cases illustrated in Section IV, in which 
the facial effect, before treatment, was that of protruded mandibles, but 
which were perfectly corrected by a forward movement of the upper 
incisors. 

UPPER PROTRUSIONS 

Fig. 9(33 will serve to partially illustrate this class of dento-facial irreg- 
ularities. This case is one in which the roots as well as the crowns 
were protruded. 

The intermediate stage of the operation shows conditions after the 
crowns of the labial teeth had been retruded following the extraction 
of the first bicuspids, with an apparatus similar to that shown in Fig. 964. 

It will be seen that notwithstanding the fact that the retruded force 
was applied through the medium of the retruding bow at the gingival 
borders of the front teeth there was left quite a decided prominence 
along the upper portion of the upper lip. 

The final stage of the operation shows the greatly improved facial 
outlines after the roots had been retruded with an apparatus similar 
to that shown in Figs. 965 and 966. 

If the operation of "jumping the bite" were performed in cases of 
this character there would no doubt be an improvement of the original 
appearance of the physiognomy, by bringing the chin and lower lip into 
more perfect harmony with the upper; but this would not be correct 
treatment, because, as will be observed, the chin is not far from a 
perfect position when compared with other features of the unchangeable 
area. 

The principles involved in the correction of this class of facial deform- 
ities may be diagrammatically illustrated as follows: 

Fig. 967 is a profile view of a typical case of protruded upper teeth. 
It will be observed that the chin appears retruded. 
56 



882 



DENTO-FACIAL ORTHOPEDIA 



Fig. 968 shows the improved effect that would be produced by "jump- 
ing the bite" in bringing the lower lip and chin into more perfect har- 
mony with the upper; yet not to be compared with that perfection of 



Fig. 963 




Fig. 964 












UPPER PROTRUSIONS 



883 



symmetrical contour shown by Fig. 969, where the chin and lower lip are 
permitted to remain in their original harmonious position while the end 
of the nose and upper lip are retruded into harmony with the whole. 
The three faces have been made exactly alike with the exception — 
as shown by the cross lines— of certain mechanical movements of the 



Fig. 965 





profile outlines in the changeable area. In Fig. 968 the outlines of 
the lower zones and chin are placed farther forward, and in Fig. 969 
the outlines of the upper zones are carried back, as they would be by a 
retruding apparatus attached to the teeth. 



Fig. 906 




In comparing Figs. 967 and 969 the difference in esthetic effect is 
quite striking, and it is one also which would seem to be hardly possible 
with so little change in the outlines of a comparatively small area. By 
cutting a piece of black paper to the exact outline of Figs. 969 and 
placing it upon Fig. 967 the real and only difference in the two figures 
can be plainly seen — as in Fig. 970. 



884 



DENTO-FACIAL ORTHOPEDIA 



When such a change is produced in the features of a human face the 
difference is greatly enhanced because of the harmonious perfection of 
other contours not shown by the figures. 



Fig. 907 



Fig. 968 




Fig. 969 



Fig. 970 




It is a noteworthy fact that a very little change in the peripheral 
shape or position of certain bones of the face on which the features are 
dependent for their character and form — a change so trifling that it could 
hardly be measured — resulting in a slight filling out or depression of 



UPPER PROTRUSIONS 



885 



certain contours, will often beautify to a remarkable degree the appear- 
ance of a face that would otherwise be quite plain and unattractive. 

This is true of all the more common cases of upper protrusion and 
retrusion which show an abnormal prominence or depression along the 
upper as well as the lower portion of the upper lip, and especially of 
those which seem to involve the entire incisive process, influencing the 
anteroposterior position of the wings and end of the nose. 




In cases of protrusion, by applying a retruding force especially 
directed to the roots and crowns of the anterior teeth, the surrounding- 
alveolar process will be forced back, allowing the upper lip to fall into 
a more graceful and easy pose, leaving the nostrils less broad and open, 
the curve of the nose straightened, and its pug-like appearance removed. 



Fig. 972 




When an upper protrusion is due alone to a labial inclination of 
large crowded teeth, with no marked protrusion over the apical zone, or 
in segment 1, the extraction of the first or second bicuspids is indicated, 
and the application of force to the crowns at such points and in such 
direction as will best overcome the malposition. 



886 DENTO-FACIAL ORTHOPEDIA 

Many instances have arisen, in the practice of dentists who were 
opposed to the extraction of teeth, when the above condition has actually 
been produced in the operation of crowding irregular teeth into align- 
ment that were too large for an already perfectly harmonious maxillary 
arch (see Figs. 992 to 995 inclusive, in Section V). 

Instances frequently arise in which the position and labial inclination 
of the upper anterior teeth produce a relative protrusion of the incisal 
zone and a contrusion of the apical, with a protrusion of the lower 
portion of the upper lip and a slight depression of the upper portion, 
deepening the naso-labial depressions (see Figs. 971 and 972). If the 
depression of segment 1 be not too pronounced, it may be restored by a 
slight forward movement of the anterior apical zone, accomplished in the 
retrusion of the incisal zone — by force applied at the incisal ends of 
the teeth alone, with the view of producing, as far as possible, a fulcrum 
force at the lingual margins of the alveola. 

With marked cases of this character the protruded position of the 
uppers demands the extraction of the first or second bicuspids, and 
then if the roots of the labial teeth are decidedly retruded it will be 
found necessary to employ a contouring apparatus to move the roots 
forward while the crowns are retruded with the fulcrum bow of the same 
apparatus. 

In contradistinction to this class of deformities, there is another 
quite as common — although not so frequently recognized as an abnor- 
mality—in which all the conditions are reversed, in that the teeth have 
a lingual inclination with protrusion of the apical zone and maxillae. 

The teeth of these cases are commonly regular in alignment, and 
owing to their lingual inclination the occlusal zone may be in proper 
relative position (Fig. 973). 

The facial imperfection which consists principally in a prominence 
or bulging along the higher portions of the upper lip and in the region 
of the nasal alse is often quite pronounced. When this is caused partly 
by the canine roots the difficulties are much increased in the case of 
patients older than thirteen years. The fact that the roots of the canines 
are surrounded by the most dense portion of the alveolar process, and their 
movement bodily in a posterior direction requiring the resorption of a 
large portion of bone, makes this operation one of the most difficult in 
dental orthopedia, even though the first premolars are extracted to permit 
the movement. 

Fig. 973 is from the models of a patient over twenty years of age, 
and will serve to illustrate a case before and after treatment of abnormal 
protrusion of the roots of the upper anterior teeth, alveolar process, and 
maxilla? — the axis of the incisors being inclined lingually. 

It will be observed that the canines have been moved bodily in a 
distal direction notwithstanding the advanced age of the patient. 

If regulating appliances are properly constructed that will permit 



Upper dental and maxillary retrusions 



887 



the production of an independent static fulcrum at the occlusal ends of 
the teeth, so that the entire power of the machine may be directed and 
maintained upon the roots (see Figs. 1014 and 1015, in Section VI), 
perfect contrusion of the prominence will slowly but surely result. 

If the teeth are crowded, overlapping, or turned on their axes, a 
correction of alignment may require the extraction of a bicuspid on 
each side in order to regulate them without an abnormal protrusion of 
their crowns. This is especially indicated when much retrusion of the 
canine roots is desired. 



Fig. 973 




UPPER DENTAL AND MAXILLARY RETRUSIONS 



Facial imperfections which are due to insufficient fulness of contour 
in the central features of the physiognomy are quite common, and vary 
in degree from conditions that are hardly noticeable to those which may 
well be classed among the most unhappy of facial deformities. 

There are several distinct types of this class of facial irregularity 
which are mainly due to an interruption in the development of the 
superior maxilla, although many arise from direct inheritance. 

The primary cause of these conditions may be often very obscure 
and admit of nothing more tangible than conjecture, and, not unlike 



DENTO-FACIAL OPTHOPEDIA 

many of the causes of irregular teeth, be really immaterial to the work 
of correction. 

Retruded Upper Incisors and Intermaxillary Process. — In the more 
pronounced deformities of this class the physiognomy will often appear 
flattened, with prominent cheek bones and protruding chin and lower 
lip; the upper incisors occlude evenly with or posterior to the lower 
incisors, and at times are extensively inlocked in this position, as instanced 
by the case fully described and illustrated in Section I. 

The upper incisors, which alone have their origin in the incisive 
process, are in their entirety posterior to a normal relative position. 
The labial inclination of the crowns, together with the deepened incisive 
fossae, will show at once the contruded position of the roots and their 
maxillary surroundings. 

Fig. 974 




The upper lip resting upon the retruded teeth and the overlying 
process is proportionately depressed. Nor does the facial defect end 
here. The entire lower portion of the nose, supported as it is by the 
nasal cartilages which spring from the anterior nasal spine and lateral 
borders of the nasal orifice, is often decidedly affected in shape by the 
retruded position of its supports. 

When there is a decided retrusion of the entire upper lip and lower 



UPPER DENTAL AND MAXILLARY RETRUSIONS 



889 



portion of the nose, with alae resting in deep depressions caused by the 
unusual prominence of the naso-labial folds, the effect is that of an 
abnormal protrusion of surrounding parts, producing at times a startling 
expression of maturity that is only common to persons of advanced age. 
This expression can be seen in Fig. 974, which is that of a girl only 
twelve years of age, and will serve as a type of cases commonly met 
with in practice. 



Fig. 97; 



Fig. 976 




Fig. 977 



Retruded and Contracted Denial and Maxillary Arch. — In this class 
of deformities the physiognomy, in the more pronounced cases, has 
much the same characteristics as those described above, but presenting 
a more general retraction of the central features, with less pronounced 
naso-labial folds. The nose is often thin and the nostrils pinched; and 
although the end of the nose may be 
depressed, the distance from the tip to 
the more depressed lip is often length- 
ened. If the patient is a "mouth- 
breather" with the typical "open bite," 
the deformity and the difficulties attend- 
ing its reduction will be greatly in- 
creased. 

Fig. 975 is from a profile model of a 
face of this class. Fig. 976 is from the 
same model photographed at a slightly 
different angle to show the angularity of 
the features. 

Fig. 977 is a view of the teeth in natural occlusion. The lower first 
premolars have been removed preliminary to retruding the anterior teeth 
to reduce the abnormal protrusion of the lower lip and esthetically 
deepen the curve between the border of the lip and the chin. The 
figure has the appearance of a perfect occlusion of all the molars, whereas, 
on account of the very great narrowness of the upper jaw, the buccal 




890 DENTO-FACIAL ORTHOPEDIA 

cusps of the second molars only, occluded with die lingual cusps of the 
lowers. 

Fig. 978 shows palatal views of the upper arch before and after treat- 
ment. 

Fig. 978 




Fig. 979 is a view of teeth in natural occlusion after treatment. The 
entire upper dental arch, especially at the apical zone, was considerably 
enlarged. The "open bite" was partially closed by grinding the molars 
and partly by extruding the teeth anterior to the molars with small 
rubber bands extending from the upper to the lower teeth. Fig. 980 
is from a model of the face after treatment. 




Fig. 980 




As mentioned in Section II, a depression of the central features 
such as described is often mistaken for a prognathous jaw, and treated 
accordingly. 

A slight retraction of the lower jaw will in nearly every case of this 
character produce an improvement in the facial aspect, because the chin 
and lower lip are brought into more perfect harmony with the depressed 
central features. Such a change, however, when it is not demanded, 
can never cause the beautifying effect produced by forcing the depressed 



UPPER DENTAL AND MAXILLARY RETRUSIONS 



891 



facial features — in segments 1 and 2 — forward, thus bringing into 
perfect harmony the entire physiognomy. 



Fig. 981 



Fig. 982 




This can be verified with any profile view of a typical case — as Fig. 
981. Fig. 982 is the same face, except that the chin and lower lip have 



Fig. 983 



Fig. 984 




been retruded, producing a certain improvement, but not to be com- 
pared with Fig. 983, where the chin and lower lip retain the same relative 



892 



LENTO-FACIAL ORTHOPEDIA 



position to the unchangeable area as in Fig. 981, while segments 1 and 2 
have been carried forward, with a result which proves (not alone in 
theory, but in practice) this to be the only true course to bring about 
an harmonious and esthetic adjustment of all the features of the physi- 
ognomy. Fig. 984 shows the actual difference, which may be verified 
upon trial, between Figs. 981 and 983. 

Fig. 985 will serve to illustrate the common result in practical oper- 
ations of this character. 

The contouring apparatus (Fig. 1011) that is used to accomplish these 
results is fully described in Section VI. With it the apical zone of 

Fig. 985 




the anterior teeth may be enlarged and advanced to any desired degree ; 
while the movement and inclination of the crowns are under the per- 
fect control of the operator. 

In this operation it will be found in a majority of cases, and especially 
with those which are begun as early as thirteen or fourteen years of age, 
that the entire incisive portion of the upper jaw may be carried bodily 
forward with the roots of the incisors. 

The depressed features of the physiognomy — in segments 1 and 2 
— that are dependent for their contour upon that portion of the maxillae 
are thus brought into perfect harmony with other features of the face. 

It is not here implied that there are not many cases of real prog- 



THE SAVING AND EXTRACTION OF TEETH 893 

nathous mandible in which its retraction, if possible, would produce a most 
desirable result; nor that such an operation is impossible if recognized 
and treated sufficiently early with properly adjusted apparatus per- 
sistently worn. The body of the mandible can certainly be forced back 
to a more posterior position in its relations to the upper, partly by bend- 
ing the rami and necks of the condyles, and partly by absorption of the 
posterior wall of the glenoid fossse. 

The many failures that have attended these operations have been 
largely due to the advanced age of the patients and much to the fact 
that the apparatus is dependent upon the will or caprice of the patient 
for its persistent application. 

On account of the early maturity and ossification of the mandible 
these operations should be undertaken as early as from five to ten years 
of age. 

The caps fitted to the head and chin should be made to exert a uniform 
pressure over the surfaces upon which they rest, admit of free ventila- 
tion, and the whole apparatus when in place should have no projecting 
parts which will interfere with the comfort of the patient at night. 



THE RELATIONS OF THE PHYSIOGNOMY TO THE SAVING AND 
EXTRACTION OF TEETH 

In its widest scope this subject includes the propriety of saving, and 
on the other hand, the propriety of extracting certain teeth of the decidu- 
ous as well as the permanent dental arches which in any way influence 
the prevention, the production, or the correction of dento-facial irregu- 
larities. Two phases of this subject will be here presented. The first 
will be in regard to the saving or the extraction of the upper premolars 
for patients older than fourteen years, to correct a dental irregularity; the 
second will deal with the early extraction of the premolars to prevent 
an abnormal upper protrusion. 

In the common form of dental irregularity shown by Fig. 986, espe- 
cially if only the model of the upper jaw were the subject of study, it 
would in all probability be decided to extract the first premolars as the 
best course to pursue as a first step toward securing a perfect alignment 
of the dental arch ; and the proceeding would be probably correct as far 
as the upper teeth alone were concerned. And again, if both upper and 
lower models were studied in occlusion and the irregularity of the lower 
arch was — as is usually the case — in correspondence with that of 
the upper, as shown in Fig. 987, the extraction of the lower first pre- 
molars would doubtless, and correctly, be decided upon. This plan of 
correction might even be decided upon after a superficial study of the 
face of the patient, which we may suppose to be similar to that shown 
in Fig. 988. Certainly the extraction of the lower first premolars which 



894 



DEN TO-FACIAL ORTHOPEDIA 



have just begun to erupt, and the retraction of the anterior teeth would 
reduce the apparent protrusion of the lower lip and bring it into more 
perfect harmony with the depressed upper lip. 

Yet when this face is carefully studied from the higher standpoint 
of esthetic development it becomes evident that the chin and lower lip 
are not protruded, in their relations to the malar prominences, the 



Fig. 986 



Fig. 987 





bridge of the nose, and the forehead, but that the central features of the 
physiognomy are depressed even to a decided retraction of the lower 
portion of the nose; and that which is really demanded in this case is the 
advancement or forward movement of the entire intermaxillary portion 
of the jaw and incisor teeth; and further, every tooth in that dental arch 
is necessary for the ultimate retention of the several parts in their 
corrected position. 





Fig. 988 








W ^f ;', 




£uv jfiw 



Fig. 989 




In the correction of malformations which denjand the protrusion of 
the incisors bodily with the roots and intermaxillary process, the posi- 
tion of the canines, as in this case, will frequently prevent the proper 
attachment and application of apparatus for producing the desired 
effect; so that it often becomes necessary to first enlarge the dental arch 
and force the crowns into partial alignment by ordinary means, prepar- 



THE SAVING AND EXTRACTION OF TEETH 895 

atory to placing the incisors in the grasp of contouring forces. Fig. 
989 shows the position of the teeth in this case in the intermediate 
stage, the crowns of the incisors being forced forward to a partial 
alignment, and with no special facial improvement. (It may be added 
that at this stage in the operation, cases of this kind have been con- 
sidered finished, until it was found possible to enlarge the apical arch.) 

Fig. 990 Fig. 991 





Fig. 990 shows correctly the final result, which was accomplished 
with the contouring apparatus described in Section VI. It will be 
seen that the incisors are in an upright position and there is now ample 
room for all the teeth, while the remarkable improvement to the physi- 
ognomy is poorly shown by the face model Fig. 991. 

Another case, that of the upper arch, Fig. 992, if examined alone 
and compared with the upper of the former case, or Fig. 986, will be 




Fig. 993 




found very similar. The same crowded condition of the teeth, the same 
lack of sufficient room for the proper eruption of the canines; and yet 
this is from the model of a case that absolutely demanded the extraction 
of the premolars. At fourteen years of age the irregularity presented 
the appearance shown in the illustration Fig. 993, showing the models 
of the case in occlusion. The patient was placed in charge of a dentist 



896 



DENTO-FACIAL ORTHOPEDIA 



who attempted the correction of the irregularity without removal of the 
first bicuspids. Fig. 994 shows the result two years afterward. 

It will be seen that the incisors were forced forward to a decided 
labial inclination, for the purpose of crowding the canines into align- 
ment; and all the anterior teeth are turned on their axes so as to occupy 
the least possible space. Fig. 995 is from the model of the face of the 
patient at that time. 

That a mistake was made in the plan of treatment pursued is evi- 
denced by the following considerations: First, the protrusion of the 
crowns of the upper anterior teeth produces an unhappy expression 
of the mouth that is equivalent to a deformity, and one that could not 
be remedied in this particular until certain members of the dental arch 
were removed. Second, if it were a case in which the maxillary arch 
was too small, with a depression of the overlying features of the face, 
the decided labial inclination of the teeth could be overcome bv an 



Fig. 994 



Fig. 995 





enlargement of the apical zone, which would have permitted a slight 
retrusion of the occludal zone with a partial, if not complete, regulation 
of the dental and facial deformity. But this was not the condition, 
and therefore could not be considered. The third and most effective 
argument is one which should never be overlooked in all cases where 
the crowns flare outward. The conical shape of the teeth permits them 
to stand in perfect alignment, although with a decided labial inclination; 
but in this position the interproximate spaces so necessary to the preser- 
vation of the teeth are so completely closed as to cut off the union of 
interproximate gum tissue, which must ultimately result in the resorp- 
tion of the gum and alveolar process and all the dire consequences that 
follow. 

Had the first premolars been extracted, many difficulties in the regu- 
lation of the teeth would have been removed; and what is of far greater 
importance, there would have been a satisfactory result in the dental 
arch and physiognomy. Or even further, had the upper first premolars 



THE SAVING AND EXTRACTION OF TEETH 



897 



been extracted as soon as they erupted, together with the deciduous 
canines, as will be outlined in the second phase of the subject, the case 
would have required little or no other treatment. 

Fig. 996 shows the present position of teeth after regulation, by 
retruding the anterior teeth to fill spaces caused by the extraction of the 



Fig. 996 



Fig. 997 





Fig. 998 



premolars. Fig. 997 is from a model of the face after treatment. It will 
be seen that the interproximal spaces between the teeth are restored, 
while the retrusion of the anterior teeth allows the lips to fall gracefully 
into proper position. The improvement in the facial aspect of this and 
all other cases cannot be fully shown by a plaster model of the face. 
Fig. 998 was made from a photograph 
of this patient, taken a few months 
after the completion of treatment. 

There are many instances where the 
early extraction of the premolars, as 
soon as they can be reached with the 
forceps, is demanded. For example, 
adult faces with decided protruding 
upper jaws and teeth, and with a 
bulged appearance about the lower 
portion of the nose. The teeth are 
commonly large, prominent, and 
crowded, although not always labially 
inclined. 

The ordinary upper protrusions which come under this head are 
so common they will require no further explanation or illustration. 

Upper protrusions where the teeth are not labially inclined are not 
quite so common. The alveolar arch is necessarily prominent, although 
the deformity in the main, as in the more common forms of protrusion, 
is due to the large size of the maxilla proper, which is far out of pro- 
portion to the delicately chiselled features which it supports and forces 
57 




898 



DENTO-FACIAL ORTHOPEDIA 



into unsymmetrical contours. The naso-labial depressions in which the 
wings of the nose rest are more or less obliterated, as would be occa- 
sioned by the sting of a bee or an alveolar abscess. The nostrils are 
broad and open, and the end of the nose forced forward and upward 
(retrousse) by the protrusion of the spinous process and cartilaginous 
septum. The upper lip, being stretched over its inharmonious frame, 
is shortened so as to cover the teeth with difficulty, and in action readily 
rises to an unpleasant exposure of the teeth and gums. 

This is an extreme, although not an uncommon, condition. Every stage 
from this to perfect harmony characterizes the innumerable varieties of 
a certain type of physiognomy. 

Fig. 999 is from the face model of a young man, aged eighteen years, 
and may be taken as a type of this character of facial deformity. 
Fig. 1000 shows the teeth in occlusion. The canines and canine emi- 
nences are very prominent, and extend high up under the wings of the 
nose. 

Fig. 999 Fig. 1000 





Had this case received the early treatment here advocated the 
deformity would have been prevented, and the almost insurmountable 
difficulties attending its reduction during nearly three years of constant 
treatment altogether avoided. 

Anyone who has never attempted to move the roots of the canines 
in a posterior direction for patients older than sixteen years cannot 
appreciate the difficulties of such an operation. And while the result 
in this case is quite satisfactory under the circumstances, as will be 
seen by Figs. 1001 and 1002, the physiognomy is not nearly so perfect 
esthetically as it would have been had the case received proper early 
treatment. 

The important consideration from a surgical and artistic standpoint 
in nearly all cases of marked upper protrusion is: Has not nature 
been forced to produce these conditions, wholly or in part, to accommo- 
date teeth that were too large for the natural or inherent frame and 
overlying features? And could we have helped nature in the early 



THE SAVING AND EXTRACTION OF TEETH 



899 



years of development by making it unnecessary for her to produce this 
excessive growth of bone for the development and sustenance of all 
these large teeth ? 

This is true of all protrusions that are caused by the inheritance of 
inharmoniously large jaws crowded full of teeth. 

We certainly cannot reduce the size of the teeth, but we can reduce 
their number, and in so doing reduce the size of the destined maxillary 
and dental arch. But we must make no mistake. The danger of advo- 
cating such a principle to those who have given this branch of dentistry 
little thought is that teeth may be extracted to accommodate an over- 
crowded condition in the arch, with little or no thought of the physi- 
ognomy, and too when a careful and properly pursued study of the features 
and their comparison with the parental types will show that in reality 
the dental and maxillary arch should be enlarged, and every tooth 
of the greatest importance in its development and retention. 



Fig. 1001 



Fig. 1002 





How are we to study the undeveloped face of a child, every lineament 
of which is passing through rapid changes of growth, with a view of 
determining whether or not the dental arch and jaws will be too prom- 
inent, or that other features will not enlarge to a harmonizing propor- 
tion? 

■ A most wonderful provision of nature in dentition causes the full- 
sized crowns of teeth to erupt, as regards time, somewhat in proportion 
to the natural growth and enlargement of the jaws. And even when 
they do not erupt earlier than is normal, or when their natural eruption 
is not interfered with by the premature extraction of the deciduous 
teeth, they are usually obliged to take an irregular position or attitude 
at first, and await the growth of the jaw which permits them to become 
regular. 

It is perhape a safe general rule to never extract a permanent tooth 
for the purpose alone of correcting a dental irregularity, unless the jaw 
has ceased growing; and never then unless it is shown by a careful study 



900 DENTO-FACIAL ORTHOPEDIA 

of the position of the teeth — their relation and occlusion — that the 
dental arch should not be expanded; or by a study of the physiognomy, 
that the alveolo-dental arch should not be enlarged? 

In a study of the relations of the teeth, the jaws, and the physiognomy 
of a child with the view of determining the advisability of extraction 
to correct or prevent the ultimate production of a facial deformity or 
marked imperfection of the features, it may become necessary to study 
the physiognomies of both parents, and possibly other members of the 
family, to correctly determine the influence exerted by inheritance. 

In this comparison of temperament, physical frame, features, and 
teeth, it may require no more than a glance to furnish all the data that 
will be of practical use. 

Usually but one parent accompanies the little patient, and a study of 
that one physiognomy may be a sufficient guide; if not, other members 
of the family should be seen. 

If there be a marked difference in the parents it may not be difficult 
to determine from which the child has inherited the teeth, by the pecu- 
liar shape and size of the incisors alone. But in regard to the maxillae 
in an undeveloped condition there will be more difficulty, although it is 
well to remember that the deciduous teeth are rarely irregular or dis- 
proportionate in size to the frame and facial features. If, therefore, 
there be a more than natural difference in the size of the permanent 
and deciduous teeth it will indicate union of inharmonious types. 

In this connection it must not be forgotten that the crowns of the 
permanent incisors are almost invariably far too large for their undevel- 
oped surroundings. The apparently disproportionate size of the central 
incisors to that of the jaw is a subject of frequent and anxious parental 
comment. If the occlusion of the incisor teeth be far from a normal 
type in their anteroposterior relations, and the same condition exists 
with either parent, it is an indication of what the child will become 
if unaided by dental skill, especially if a similarity be noted in other 
particulars. 

With differences in temperament, compare general shape and size of 
the eyes, brows, ears, and teeth. 

Other features are so subject to change in the processes of natural 
growth and development that they cannot be relied upon to furnish 
legitimate data. For instance, the nose may change in a few years of 
late youthful development from one originally small and short — and 
over the nasal bones decidedly depressed — to a form different in every 
particular. 

All these things are of the utmost importance in determining the 
impropriety of extracting certain teeth to reduce an apparent abnormal 
protrusion, which may in time become symmetrical in its relation by 
the natural growth of the jaws and other features; and also the equally 
culpable error of saving teeth, or the failure to extract teeth, whose 



THE SAVING AND EXTRACTION OF TEETH 901 

very presence in the arch obliges nature to reproduce a parental de- 
formity, or produce an acquired deformity. 

For a child with a marked upper protrusion similar to Figs. 1003 
and 1004, with teeth prominent and crowded in an arch which does not 
admit of correcting by a lateral expansion, extract the first bicuspids as 
early as possible, even before their eruption is completed, together with 
the deciduous canines — unless it be one of those very rare instances 
where the first permanent molars cannot be saved. 

The same is true of the lower, when there is reason to believe there 
will be a disproportionate overdevelopment of the lower dental arch. 

In the ordinary course of eruption the development and eruption of 
the permanent canines are doubtless more influential than those of 
other teeth in emphasizing a protrusion of the central features of the 
physiognomy. 

Fig. 1003 Fig. 1004 




In the course of their eruption they are obliged to crowd into align- 
ment along the mesial surfaces of the roots and crowns of the first 
bicuspids — which at this time represent the immovable bases of the 
arch — with the result that the incisive and intermaxillary portion of 
the arch is forced forward to a more pronounced position. This move- 
ment has been shown to be not impossible or difficult of attainment by 
artificial force, even much later in life. 

With the first bicuspids and deciduous canines removed sufficiently 
early there are numberless instances w T hen the arch, anterior to the 
second bicuspids, would be diminished the width of a bicuspid, without 
resort to artificial means. 

By the exertion of a slight traction force from an occipital base of 
anchorage the sockets of the temporary canines will be closed by the 
permanent laterals, and the permanent canines in the course of their 
eruption will be deflected into the alveoli of the extracted bicuspids. 

Figs. 1005 and 1006 represent one case out of many under treatment 
by this method, although not all by the occipital method, Fig. 1007 shows 



902 



DEXTO-FACIAL ORTHOPEDIA 



the position of the teeth after about two months of traction force from 
molar anchorages; the protrusion not being so pronounced as to demand 
the use of the skull-cap. 

It will be seen by the canine eminences— although far better shown 
upon the model itself — that the position of the canine crowns is imme- 



Fig. 1005 



Fig. 1006 





diately over the former alveoli of the first bicuspids. As they continue 
to grow downward in this somewhat open channel, their roots, which 
are not at present developed, will grow upward, the teeth in their entirety 
finally taking a position and inclination similar to that of the bicuspids 
which they replace, and considerably posterior to that which they were 
otherwise destined to occupy. 



Fig. 1007 




The patient, aged nine years, had the teeth, eyes, ears, and general 
temperament of the father, whose upper arch was abnormally protruded 
in a similar manner, which was the raison d'etre for dental aid. 

Had the father's teeth been in proper relative and symmetrical 
position, and similar to the son's in other particulars which could be 
legitimately used as data, it would have been an argument in favor of 



THE CONTOURING APPARATUS 903 

non-extraction with the expectation of other treatment later; but it should 
not have been passed upon without seeing the mother. Had the mother's 
teeth been found small and the general physical features cast in a more 
delicate mould than her husband's, investigations along other lines 
would have been required, with the view of determining if the child 
had not the large teeth of the father associated with facial bones that 
would always be inharmonious in size. 



THE CONTOURING APPARATUS 

The limited area upon which force can be applied to a tooth, com- 
pared with that portion covered by the gum and embedded in a bony 
socket, has made it next to impossible, with all ordinary methods, to 
move the apex of the root in the direction of the applied force; nor 
could this ever be accomplished with force exerted in the usual way at 
one point upon the crown, however near the margin of the gum it may 
be applied, for the opposing margin of the alveolar socket must receive 
the greater portion of this direct force, and in proportion to its resist- 
ance it will become a fulcrum exerting a tendency to move the apex of 
the root in the opposite direction. 

Fig. 1009 





But if in the construction of the apparatus a static fulcrum is created 
independent of the alveolar process at a point near the occluding portion 
of the crown, while the power is applied at a point as far upon the root 
as the mechanical and other opportunities of the case will permit, the 
apparatus becomes a lever of the third kind, the power being directed 
to a movement of the entire root in the direction of the applied force. 

This proposition is made plain by reference to diagrams. In Fig. 
1008 let A be a point upon a central incisor at which force is applied in 
the direction indicated by the arrow, then the opposing wall, B, of the 
alveolar socket near its margin will receive nearly all of the direct force; 
and in proportion to its resistance there will be a tendency to move the 
root in the opposite direction. This will also hold good even if the 
force be applied at A, Fig. 1009, or as far upon the root as may be per- 
mitted by attaching a rigid upright bar, C, to the anterior surface of the 



904 



DENTO-FACIAL ORTHOPEDIA 



crown; the only difference being that the direct force is distributed 
over a greater area. But if, as in Fig. 1010, to the lower end of C a 
traction wire or bar, F, is attached, and if the mechanical principles of 



Fig. 1010 




the machine be further enforced by uniting its posterior attachment to 
the anchorage of the power bar P, the anchorage force will be materially 



Fig. 1011 




neutralized and an independent static fulcrum at D created. The 
apparatus now will distribute its force over the entire root, and give 
complete direction and control of whatever power is put into it. The 



THE CONTOURING APPARATUS 905 

entire tooth may be carried forward bodily or either end may be made 
to move the more rapidly. The force thus directed to the ends of the 
roots will have an increased tendency to move the more or less yielding 
bone in which they are embedded. 

For practical illustrations of what has been accomplished by an 
apparatus of this kind in moving the upper labial teeth forward bodily, 
see cases described in Sections I, IV, and V. 

As nearly all irregularities of this class demand a protruding movement 
of the upper labial teeth, with the view of carrying forward with the roots 
the labial alveolar ridge and incisive process, it is of the greatest impor- 
tance that every detail in the modern construction and application of 
the only apparatus calculated to effectively perform this work should be 
fully understood, as upon this will largely depend the real success of the 
operation. 

The drawing represents the regular protruding contour apparatus, 
adapted for all pronounced cases of this class in which a considerable 
bodily protruding movement of the upper labial teeth is demanded. 
The scientific principles of movement accomplished by this apparatus 
have been fully explained. In this apparatus the power bow is No. 13 
extra hard German silver. The rootwise bar attachments on the incisor 
bands are also cut from the same size of wire, and are formed to receive 
the force of the bow above the gingival borders. 1 

Provision should always be made for the attachment of the intermax- 
illary elastics at the distal extremities of the anchorages. If the second 
molars have erupted, these teeth should be joined to the anchorages 
for the attachment of the buccal hooks as shown. Otherwise, the elastic 
bands are looped over the distal ends of the fulcrum tubes. 

The teeth should be properly separated, and each finished band 
and anchorage so perfectly fitted that it can be easily forced on and 
off with the aid of a wood plugger and band removing pliers, 2 to 
make slight but necessary changes in the shape or position of the 
attachments or power bow. The power bows for extensive move- 
ments are always No. 13 extra hard. They should be bent, first 
upon the model and finally at the chair, to conform to the shape 
of the arch, and their ends to lie evenly in the power tubes without 
the slightest tension. In the final moves of this important requirement, 
place the anchorages in position and the power bow with the threaded 
ends lying along the outside of the tubes. Then place the right end in 
its tube and see that the other lies exactly parallel with the left tube and 
in proper shape and position in front. Then place the left end in its 
tube with the other end free, and go through the same movements. 

1 For the construction of the anchorages, see Stationary Anchorages, Chapter VII, 
Dental Orthopedia, and then turn to B. 91 for directions in placing and soldering 
the fulcrum and power tubes. 

2 Ibid. 



906 



DENTO-FACIAL ORTHOPEDIA 



This may require repeating several times, with the greatest nicety of 
judgment and patience in detail, before you are able to assemble the 
bow and anchorages properly together. The heavy bending pliers, 
Fig. 1012, are indispensable for this operation. 

In assembling the power bow with the anchorages, after it has been 
properly shaped, insert one end in its tube with the anchorage in place, 
then slip the tube of the other anchorage on to the free end of the bow and 
force it to place on the teeth. These movements should be observed 
in the final cementing of the anchorages, as it would be impossible to 
place the rigid bar otherwise. In the preliminary assembling after the 
anchorages and bow are properly placed, the labial bands which have 
been previously fitted to the teeth are placed in position, with their 
rootwise extensions resting over the bow. It may be found at this time 
that the bow will require lifting or lowering slightly by bending it at 
the sides while in position, to bring it to the exact position to be clasped 



Fig. 1012 




by the extensions. The latter will also usually require bending and 
filing to fit them to the requirements of the bow. The ends are filed 
on the gingival side to a flattened taper, which should extend a trifle 
beyond the bow with a slight lingual curve, to aid them in retaining 
their position under tension. 

In the shaping and fitting of the rootwise attachment and bow, the 
greatest care and consideration should be exercised. First, the bands 
for extensive movements should extend nearly to the highest gingival 
border of the gum, and from that point the rootwise extensions should 
bend forward so as to freely clear the borders of the gum, and then 
back to a position to slightly overlap the power bow. 

The difficulty of bending the rigid extensions to a sharp angle, if 
necessary, without injury to their band attachments, may be overcome 
by using the special pliers shown in Fig. 1013, which is made to clasp the 
band and its attachment firmly, while the extension is given the desired 
shape with pliers and file. Second, the power bow should rest slightly 



THE CONTOURING APPARATUS 



907 



above the highest marginal points of the central incisors and, in the final 
fitting, conform to the shape of the gum, but freely clear its surfaces. 
This is very important as the natural swelling of the gums in the oper- 
ative action will be greatly increased by any undue pressure of the bow. 
Should this be found to be a fact at any time during the operation the 
labial bands should be removed, and the extensions, upon which the 
relative position of the bow to the gum depends, should be bent forward 
so as to free the bow from its embedment in the swollen gum. Third, 
in the original shaping of an upper power bow it will be usually advis- 
able to curve it downward at the median point to prevent it from inter- 
fering with the free action of the frenum. 

Before removing the temporarily assembled apparatus, the bow 
should be marked on each side of the respective rootwise extensions, 
for guide markings to cut the square grooves, shown by the drawing, 
in which the extensions rest while in action. In the final cementing of 

Fig. 1013 




the labial bands, they are simply carried to their respective positions 
on the teeth and bow. The fitting and placing of the fulcrum bow 
No. 22 is the same as for the small alignment bows which are threaded 
at one end. 

Treatment Adjustments. — In applying the force which is to follow the 
first conscious tension of the nuts, the large nuts of the power bow should 
be given about two quarter turns three times a week. As the movement 
advances it will become necessary to unscrew the fulcrum nut occasion- 
ally to allow the incisal zone to move forward with the roots. If the roots 
are found to be moving dangerously fast for the safety of their vitality, the 
application of force should be stopped in the power bow, and if necessary 
the nuts may be unscrewed slightly. Unscrewing the nut upon the 
fulcrum bow is also equivalent to reducing the force upon the roots. It 
may be advisable to cut and remove the fulcrum bow entirely, to be 
replaced with a new one when the danger is past. The danger line will 



908 DENTO-FACIAL ORTHOPEDIA 

be indicated by unusual sensitiveness to heat and cold over the root 
or roots of the affected teeth, which should not be allowed to arrive to 
a continual pain. Perfect rest should be afforded to the teeth and the 
gum painted with strong tincture of iodin, two or three times a week, 
until all irritation subsides. 

Those who have followed closely the directions will realize something 
of the difficulties and skill necessary for the perfect accomplishment 
of bodily moving the labial teeth for the correction of facial contours. 
The author wishes to say that unless the operation is considered of 
sufficient importance to give to it the same painstaking skill that is de- 
manded in other branches of dentistry, it had better not be attempted, 
as in all probability it will prove a failure. This refers not alone to the 
construction and application of the regulating apparatus, but to the 
construction and attachment of the proper retaining appliance that is 
intended to permanently sustain the position gained. On the other 
hand the truly wonderful work which this single apparatus has accom- 
plished in the author's hands, attested now by hundreds of cases, proves 
to him that its work in other hands will cause this principle to live and 
grow in favor. 

Fig. 1014 




An apparatus for retruding the roots of the anterior teeth is con- 
structed in a very similar manner (Fig. 1014). The direction of the two 
forces being reversed, it becomes necessary, however, to make certain 
important variations. The power bow P, now exerting a traction force, 
No. 16 will be found sufficiently large for all purposes. It is not 
flattened, but rests in grooves cut in the anterior surfaces of the upright 
bars B. The power-bow tubes should be soldered closely to the anchor- 
age bands, so that the nuts which now work at the posterior ends of the 
bow will not irritate the mucous membrane of the cheek. The fulcrum 
bow F, exerting in this apparatus a jack-screw force, should also be 
No. 16. It is flattened along its middle portion to engage with the 
occluding ends of the upright bars at D, provision being made for the 
purpose in the construction. 

The power of the two forces being so great upon the upright bars, 
with a tendency to lift the occluding ends from their attachments, and 
thus allow the free ends to press into the gum, it is important with this 



THE CONTOURING APPARATUS 



909 



apparatus that the occluding end attachments be reinforced by soldering 
to the bands an extra piece of banding material that shall extend from 
the labial face over the occluding end of the tooth to the lingual portion 
(Fig. 1015). 

After the joint of the band has been soldered, the reinforcing piece, 
of sufficient length for the purpose, should be soldered to the labial 



Fig. 1015 




face alongside of the joint; then the band is perfectly fitted to the natural 
tooth — the extra piece being bent over and burnished to its position 
on the labial surface, and the position of its end distinctly marked upon 
the band, to serve as a guide to soldering. 

When the hoods are completed in this way and finally all placed on 
the tooth and perfectly fitted, an impression should be taken for fitting 
and soldering the upright bars as described for the protrusion apparatus. 



CHAPTEE XXIII 
ORAL PROPHYLAXIS 

By S. H. GUILFORD, A.M., D.D.S., Ph.D. 

When it is remembered that the mouth is the principal vestibule 
leading to the internal organs; that through it must pass all of the aliment 
designed to promote and sustain bodily function; that into it the various 
salivary glands pour their secretions, which become mingled with the 
food and then pass on to take part in the process of digestion, it becomes 
apparent that this important cavity should at all times be kept in a 
thoroughly pure and healthy condition in order that what passes through 
it may not be contaminated. 

All saliva carries with it in solution an amount of calcium salts which 
may attach itself to the tooth surfaces and afford a favorable opportunity 
for the lodgement and retention of minute food particles, which, if allowed 
to remain, undergo putrefactive decomposition, causing serious injury to 
tooth substance. 

In addition, the deposit furnishes a habitat for various forms of bac- 
teria, which, passing into the stomach, may interfere with the process 
of digestion, or their toxins may produce pathological conditions which 
will, to a greater or less degree, affect the health of the individual. 

Oral prophylaxis is that branch of dental science which has for its 
object the maintenance of a clean and healthy condition of the oral 
cavity. This can be brought about only by the skilful and conscientious 
service of the dental practitioner conjoined with the utmost care and 
diligent cooperation on the part of the patient. 

While it has long been known that caries of the teeth could be greatly 
minimized and largely prevented by the careful and frequent removal of 
foreign deposits and accumulations from and between the teeth, it is 
only recently that the profession and the laity have awakened to the fact 
that the oral cavity could be so carefully kept as always to be in a healthy 
condition, and that when in this condition many ills hitherto unaccounted 
for would be prevented. 

Once the dental practitioner felt that his duty was performed when 
he had removed the most visible deposits found upon the teeth whenever 
the patient happened to present for other service, adding, perhaps, a 
word of advice as to the more frequent use of brush and powder. No 
effort was made to impress upon the patient the value of this personal 
care other than that it would measurably prevent future caries, neither 
(910) 



ORAL PROPHYLAXIS 911 

was he urged to present himself at frequent and fixed intervals for 
inspection and professional assistance in the way of prophylactic treat- 
ment. 

Xow, in the light of fuller knowledge, the practitioner has come to 
regard himself as the custodian of the patient's mouth, and feels it to be 
part of his professional duty to fully explain the importance of oral 
hygiene and emphasize the necessity for constant watchfulness and 
care if the dental organs are to be preserved for a lengthened term of 
years and the general system measurably protected from the disturbing 
influence of pathogenic organisms. 

When the patient has once been fully impressed with the necessity 
for unremitting care on his part, and the importance of periodic visits 
to the dentist, the foundation will have been laid for the best results that 
oral prophylaxis can accomplish. 

In beginning the treatment for a patient, the first requirement is that 
the teeth be carefully examined, and then by proper instrumentation 
freed from all hard deposits found upon any of the exposed surfaces of 
the crowns and also from the lesser deposits that often lie beneath and 
are concealed by the free margin of the gum. 

So carefully should this part of the operation be performed, that when 
completed no calcareous matter may remain anywhere upon the teeth. 
Next, the labial, lingual, and buccal surfaces should be gone over and 
further cleaned with orange-wood stick and pumice, rigorously applied. 
This will not only remove any minute portions of ordinary foreign matter, 
but also such gelatinous plaques or accumulations of inspissated mucus 
as are most generally present. After this the stick and pumice should be 
used upon such portions of the approximal surface as can be reached 
by them, and finally floss silk, charged with pumice, should be passed to 
and fro between the teeth to cleanse and polish thoroughly the surfaces 
most nearly in contact. In this manner every part of each tooth surface 
will receive thorough treatment. 

The pumice used should be of the fine variety known as pumice flour, 
and if incorporated into a pasty mass with glycerin it will adhere better 
to the stick and floss and render more efficient service. 

This cleansing of the teeth cannot be done thoroughly if done hastily. 
The operation must be carried forward with a fair amount of delibera- 
tion, so that no single feature of it may be overlooked. If the case in 
hand is one that bears evidence of long neglect, two or three hours' 
time may have to be spent upon it in order to bring about a proper 
condition of cleanliness. In many cases it will be well to divide the 
operation between several sittings in order to avoid undue nerve-strain 
or suffering on the part of the patient. 

When once completed the patient should be given to understand that 
this first operation, while placing the mouth in a hygienic condition, is 
but the beginning of the treatment, and that it will have to be followed 



912 ORAL PROPHYLAXIS 

up by successive treatments of a similar but much milder character at 
intervals of a month or two; the frequency of the treatments depends 
largely upon the faithfulness of the patient in his personal care of the 
teeth during the intervals. 

As to the patient's part in furthering the prophylactic treatment, he 
should be instructed to brush his teeth carefully immediately upon 
arising, after each meal, and again before retiring. At least once a day, 
at one of the brushings, a dentifrice should be used to supply the necessary 
friction which the brush alone would not provide. Dental floss mu^t also 
be passed between all of the teeth after they have been brushed, and at 
any intermediate times when food has been taken. 

It should be made plain that all the details of treatment must be 
conscientiously carried out both by patient and operator if success is 
looked for, and the patient may be assured that by faithfully complying 
with the regulations laid down not only will his mouth be kept in a 
thoroughly hygienic condition and decay of the teeth controlled, but 
that recession of the gums and inflammation and destruction of the 
subjacent tissues about the roots of the teeth will be largely and often 
entirely prevented. 

One of the main contributing causes to success in oral prophylaxis 
lies in awakening in the patient's mind the necessity for the elaborate 
and persistent treatment proposed. 

As prophylaxis of the oral cavity is still a novel idea to the laity, and 
they are likely to confound it with the old and simple operation of 
cleaning or cleansing the teeth, patients may fail to realize the necessity 
for the many visits to the office and the increased cost of the frequent 
treatments. 

For this reason it is necessary for the operator, if he wishes to achieve 
the best results of treatment, constantly to hold before the patient the 
advantages that are sure to accrue from faithful and continued treat- 
ment and the dire results that are certain to result either from neglect 
or interrupted service. 

Unless the interest of the patient is aroused to the extent of making 
him a convert to the gospel of mouth cleanliness, coupled with the fear 
of early loss of the teeth when treatment is neglected, w T e can hardly 
hope for success in our efforts. 

A patient must either be won over to our views in the beginning or he 
will discontinue the treatment after a few visits and fail to realize the 
intended benefit. Patients afflicted with pyorrhea and its accompani- 
ments of pain and loosening of the teeth are usually very willing to 
undergo a course of prophylactic treatment in the hope of obtaining 
relief; but those whose dental organs and oral tissues have given them 
no perceptible trouble are not so easily converted to the importance of 
prophylaxis as a preventive measure. 

The advantages to be derived from systematic prophylactic treatment 



ORAL PROPHYLAXIS 913 

may be summarized and presented to patients in some such form as the 
following; 

1. The oral cavity will be kept in a thoroughly clean and sanitary 
condition. 

2. The breath will be free from offensive odors. 

3. Dental caries will be largely prevented by the removal of those 
active agents which are mostly responsible for it. 

4. Extensive caries cannot occur because the frequent examinations 
will disclose the very beginnings of tooth injury. 

5. Gum recession and root exposure will be delayed or prevented 
by the sanitary condition prevailing and by the gentle stimulation of 
the gum tissue induced by the frictional treatment. 

6. In like manner the irritation caused by calcareous deposits at or 
beneath the gum which promote, if they do not really produce, pyorrhea 
will be eliminated. 

7. By preventing gum irritation and controlling pyorrheal tendencies 
the teeth should remain firm and useful to advanced age. 

8. With the oral cavity kept relatively free from pathogenic organisms, 
and foreign substances undergoing putrefactive decomposition, the 
digestive functions will be less likely to be unfavorably influenced, and 
the entire system will be better in consequence. 



58 



INDEX 



Abscess, acute, apical, facial swelling 
from, 445 
second stage of, 441 

treatment, surgi- 
. cal, 442 _ 
therapeutic, 
442 
third stage of, 443 

treatment, surgi- 
cal. 443 
therapeutic, 
444 
t reatment in syphilitics, 441 
alveolar, blood poisoning due to, 124 

in deciduous teeth, 681 
apical, pathology of, 428 
around third molar, diagnosis, 439 
bone caries and necrosis due to, 453 

sinus in, 439 
chronic apical, amputation of root 
apex, 449 
calculus, 452 
diagnosis by radiograph, 

449 
replantation in, 450 
root canal filling methods, 
449 
in deciduous teeth, 
462 
rubber cups for gums, 449 
systemic complications, 

treatment, 452 
treatment, 446 

when discharging 

through fistula, 447 

when discharging 

through root canal, 

446 

in encystment of pus, 

452 
recurrent cases, 447 
dento-alveolar, causes, 432 
diagnosis, 438 
infection of meninges of brain, 

569 
morbid anatomy of, 433. 
predisposition to, 437 
systemic intoxication from, 438, 

445 
subacute, 436 

tests for vitality of tooth, 439 
treatment, 440 



Abscess, dento-alveolar, treatment, open- 
ing pulp chamber, 440 
rubber dam guard, 441 
therapeutic agents, 441 
ways of discharge, 435 
involving antrum, 439, 451 
paths of discharge, 439 
pericemental, in pyorrhea, 501 

due to pyorrhea, diagnosis, 438 
syringe, 443. 
Abscesses on deciduous teeth, 453 
Absorbent paper, 138 
Actinomyces, infection through pulp, 

123 
Adrenalin in local anesthesia. See Anes- 
thesia. 
Air syringe, 138 
Alloy and cement fillings, 331 
Alloys, 262. See also Amalgams, 
annealing, 270 
effects, 271 
Black's, 264 
buying and keeping, 289 
crushing resistance, 272 
Flagg's, 266 
silver-tin, exhibit, composition and 

physical properties, 265 
strength, 272 
Townsend's, 266 
Alveolar necrosis, treatment, 453 
process, 59 

changes following tooth move- 
ment, 733 
development, 58 
growth, 108 
in orthodontia, 726 
peridental membrane, 102 
resorption, 562 
surgical anatomy, 561 
Amalgam, Black's formulae, 264. See 
also Alloys, 
carriers and pluggers, 284 
Arthur's, 284 
_ Ivory's, 285 
cavity preparation, 277 
cement fillings and, 326 
classification, 289 
comparative behavior, 291 
constituents, 266 
contraction and expansion, 268, 293 

measuring, 294 
copper, 278 

fillings, cavity lining, 323 
heating spoon for, 288 

(915) 



91G 



INDEX 



Amalgam, copper, Kirk's electrolytic 
preparation, 288 
Fenchel's studies on, 267 
fillings, cement lining under, 328 
change in bulk, 293 
discoloration of tooth tissue, 292 
finishing, 284 
versus gold fillings, 325 
matrices in, 254 
repairing, 233 
Flagg's, 292 
flow of, 274 
gold fillings and, 329 
indications for, 277 
inlays, 327, 331 
matrix in filling, 284 
mercury, amount in mixing, 280 

effect on crushing resistance, 274 

on flow, 275 
empirical methods of mixing 
alloy and mercury, 287 
micrometers, 294 
mixing, 279 

mortar for, 280, 287 
nature, 262 

crystallization, 264 
diffusion, 264 
packing, 282 

pluggers for packing, 282 
Arthur's, 285 
Black's, 282 
Ivory's, 283 
rapid setting, 278, 291 
repairing, 233 
selection, 277, 289 
slow setting, 278, 291 
thermal and chemical relations, 276 
tin foil fillings and, 321 
use and manipulation, 277 
washing, 287 
Ameloblasts, 63 
Amputation of root apex, 449 
Analgesia, dentinal by cocain, 148 
Anchorage in orthodontia, 764 
Anesthesia, general, chloroform, 150 
dentin, sensitive, 150 
discrimination in use, 611 
ether, 613 
examination of patient before 

administration, 611 
indications for, 611 
mouth props, 559 
nitrous oxid, 618 

apparatus, 618 
Hewitt's method, 619 
and oxygen, 619 
preparation of patient, 612 
selection of anesthetic, 612 
somnoform, 150 
local, 623. 

active principle of suprarenal 
capsule and synthetic sub- 
stitute, 628 
adrenalin, 629 
anemia, local, 626 
anterior teeth, single, 645 
cocain, 630 

antidotes, 631 



Anesthesia, local, cocain solutions, 631 
substitutes, 632 
toxic symptoms, 630 
cocain-adrenalin injection, 404 
contraindication of injection in 

oral disease, 638 
cysts, 645 
dentin, 642 
diploic, 404 
ethyl chlorid, 627 

mode of application, 
628 
freezing mixtures, 627 
history, 623 
hypodermic syringes, 634 

manner of keeping, 636 
hypodermic needles, 636 
means of producing, 624 
novocain, 633 

advantages, 632 
dosage, 633 
dropping bottle, 634 
low toxicity, 633 
operations about the mouth 

other than extraction, 644 
osmotic pressure, 625 
palate, hard and soft, 645 
physiological action of anes- 
thetics, 625 
planting teeth, 657 
pressure, 642 

pulp, 642. See also Pulp Anes- 
thesia, 
suprarenin, 630 

teeth and roots, several simul- 
taneously, 639 
one-half of lower jaw, 
640 
of upper jaw, 639 
single and diseased, 638 
technique of injection, 636 

conductive mandibu- 
lar, 641 
intra-osseous, 639 
peridental, 638 
perineuria!, 639 
into pulp, 642 
rhomboid infiltration 

for tumors, 644 
subperiosteal, 637 
tongue and floor of mouth, 645 
tumors, 644 
partial by ether, 150 
Angina, Vincent's, differential diagnosis 

from pyorrhea, 500 
Angle's orthodontia, 683 
Antisepsis in dentistry, 118 

prevention of tuberculosis, 125 
Antiseptics, comparative list, 128 

definition, 128 
Antrum of Highmore, empyema, 439 

fistula treatment, 451 
Apes, tooth forms in, 24, 30 
Arches, dental and maxillary, contracted, 
889 
effect on tooth development, 722 
forces producing abnormal develop- 
ment, 835 



INDEX 



917 



Arches, importance in occlusion, 694 
main types, 19 
rounded, 20 
square, 20 
V, 20 
square, 19 
Arsenic. See also Pulp devitalization, 
in cements, 301 

in devitalizing pulps of deciduous 
teeth, 678 
Arsenical applications, accidents from, 
408 
necrosis, antidote, 408 
paste for pulp devitalization, 405 
Articulation, normal, 21 
Atavism, law of, 54 
Auto-infection in mouth, 123 



B 



Bacteria, oral, isolation for making 

vaccines, 511 
Bands in orthodontia, making plain, 

759 
Bicuspid, evolution of form, 18 
lower first, 37 
second, 39 
odontography, 23, 35 
second, anatomical considerations in 

extracting, 567 
upper first, 35 
second, 37 
Bismuth paste in pyorrhea, 503 
Bleaching teeth, 524 
agents for, 525 
cataphoresis, 539 
drugs used, 540 

Hollingsworth's apparatus, 540 
chemical considerations, 525 
chlorin, 526 

filling pulp chamber, 532 
final washing of tooth, 532 
instruments, 531 
manner of keeping drug, 531 
Truman's method, 531 
Wright's method, 533 
chlorinated soda, 533 
hydrogen dioxid, 534 

Harlan's method, 536 
McQuillen's method, 536 
Schreier's kalium-natrium 

paste, 536 
technique, 534 
and aluminum chlorid (Harlan), 

536 
and electric light, 542 
indications for, 524 
iodin, 534 
light, 542 
perhydrol, 535 
preparation of teeth for, 527 
pyrozone, 535 
removal of old fillings, 530 
root canal filling, 529 
saponification of root canal contents, 

530 
sodium dioxid, 536 



Bleaching sodium dioxid, special indica- 
tion in putrescent cases, 538 
stains, special, 542 

metallic salts, 542 
Bone, caries and necrosis due to abscess, 
453 
growth during retention, 799 
in tooth movement, 726 
Bon will's "law" of occlusion, 693 
Brachy cephalic peoples, type of dental 

arch in, 20 
Brain, inflammation of meninges from 

suppurating tooth, 569 
Bridge-work as a source of infection, 124 
Broaches, Donaldson's, 413 
Kerr's, 413 

for root canal work, 459 
sterilization, 120 
Brushing children's teeth, 682 
Burs, Boley micromillimeter gauge for 
ordering, 163 
for cavity preparation, 163 
dentate, 163 
finishing, 228 
fissure, use of, 171 



Calculus in chronic apical abscess, 452 
See also Tartar, 
salivary, chemical nature of, 474 

as predisposing cause of pyor- 
rhea. See Pyorrhea alveolaris. 
serumal, nature of, 474 
Camphor, tincture, for nausea, 200 
Canada balsam for root canal filling, 458 
Candy, effect on deciduous teeth, 682 
Canine tooth, extracting impacted, 588, 
597 
lower, 30, 32 
odontography, 23, 30 
Carbolic acid for cavity lining, 151 

for sensitive dentin, 151 
Caries, action on enamel rods, 62 

in deciduous teeth, silver nitrate in 

treatment, 669 
dental tissues in, 56 
spreading, interior, 170 
in dentin, 85 
Carnivora, tooth forms in, 18, 24, 34 
Casting, gold for, 380 

to other pieces, 381 
investments, 369, 374, 3S4 
Ritter mixer, 378 
Taggart's mixers, 375 
machines, Custer's electric, 382 
Jameson's centrifugal, 383 
Price's electric, 383 
Seymour's stamping, 383 
Taggart's pressure, manner of 
operating, 370 
nitrous oxid blowpipe for, 371 
pressure required, 381 
Taggart's system, 367 
temperature of flask, 374 
Cataphoresis for bleaching teeth, 539 
pulp anesthesia, 403 



918 



INDEX 



Cataphoresis, sensitive dentin, 148 
Cavities, classification, 156 
pit and fissure, 156 
smooth surface, 156, 178 
excavating under analgesia, 146 

See also Dentin, 
filling proximal, with gold, 258 
linings for, 322 

mesio-approximal in bicuspids and 
molars, selection of filling material, 
329 
nomenclature, 154 

angles, simple cavities, 155 
cavo-surface angles, 156 
division into thirds, 155 
point angles, 155 
simple, 156 
walls, 155 
occlusal, amalgam and gold fillings 
for, 330 
cement and gold fillings, 328 
fissure, 72 

zinc phosphate and amalgam 
fillings for, 326 
preparation, for amalgam, 277 
bicuspid for matrix, 242 
cement steps in, 241 
by classes, 166 

first step, pit and fissure, 

166 
second step, removal of 

softened dentin, 174 
third step, shaping for re- 
sistance, retention, and 
convenience, 174 
dental tissues as determining 

factor, 56 
dentin instrumentation, 177 
dovetail form, 176 
in enamel, 71 

walls, bevelling and finish- 
ing, 177 
instrumentation, 178 
explanation of terms, 239 
extension for prevention, indi- 
cations for, 244 
final touches, 178 
filling material as determining 

factor, 177 
in gingival third, 178 
for gutta-percha fillings, 314 
in incisors, 80 

for inlays, 335. See also Inlays, 
instruments, 157 
burs, 163 
chisels, 157 
disks, wheels, and points, 

164 
excavators, 157 
sharpness required, 147 
major class for matrix work, 239 
minor class, 244 
in molar, for matrix, 240 

in buccal surface of upper, 

. 75 
mortise form', 175 

in proximal surfaces of bicuspids 

and molars, 187 



Cavities, preparation, in proximal sur- 
faces of incisors and 
cuspids, 178 
incisal angle involved, 
185 
not involved, 
178 
instrumentation, 183 
smooth surface, 1 78 
steps in, 157 
technique, 153 
proximal, amalgam and gold fillings 
for, 329 
zinc phosphate and amalgam 
fillings, 327 
proximo-occlusal, cement and gold 
< fillings for, 328 
zinc phosphate and amalgam 
fillings, 328 
wiping with carbolic acid before 
filling, 151 
Cements, 296 

action of oral fluids on, 302 

Ames' copper, for deciduous teeth, 

673 
arsenic in, 301 

basic zinc phosphate, use of, 332 
contraction and expansion, 302 
fillings, alloy and cement, 331 

basic zinc phosphate and silicate 

combined, 331 
cavity linings for, 323 
combination, 325 
in deciduous teeth, 675 
finishing, 309 
with gold, 328 
with gutta-percha, 330 
matrices for, 308 
packing instruments for, 308 
protecting with paraffin, 676 
protection from moisture, 307 
for inlay manipulation, 357. See 
also Inlays, 
setting, 301 
liquids, composition and use, 299 
manner of keeping, 300 
turbidity, 301 
medicated, for pulp capping, 394 
mixing, 304 
oxyphosphate, 296 

of copper, indications for, 304 
for steps, 243 
properties and uses, 302 
removal of old root canal fillings, 431 
setting and strength, modifications, 

300 
silicate, 201, 298 

fillings, finishing, 309 
matrix for, 308 
packing instruments, 308 
properties, 304 
uses, 332 
Spalding loop for carrying, 327 
spatulas for mixing, 304 
steps in cavities, 241 
tests for volumetric changes, 302 
zinc oxychlorid, 296 

for filling root canals, 457 






INDEX 



919 



Cements, zinc phosphate, 201 

and amalgam fillings, 326 
for filling deciduous teeth, 

673 
for temporary operations, 
303 
Cementoblasts, 101, 105 
Cement urn, 94 
formation, 95 
function, 61, 68, 95 
histological description, 94 
hypertrophy, 97 
structure, 97 
Chair, cleanliness, 121 
Cheeks in dento-facial operations, 880 
Children, management of, 667. See also 

Deciduous teeth. 
Chin in dento-facial imperfections, 880 

retractor in orthodontia, 752 
Chisels for cavity preparation, 157 
enamel hatchets, 161 
formulae for, 161 
gingival margin trimmers, 162 
uses, 173 
Chlorin, instruments for applying, 531 
manner of keeping, 531 
methods for bleaching teeth, 536 
Chloroform for general anesthesia. See 

Anesthesia. 
Chloropercha for root canal filling, 457 
Clamp-bands, Angle's, 745 
Clamps for rubber dam, 196 
Delos Palmer's, 197 
Huey's, 196 
Southwick's, 196 
Woodward's, 217 
Cocain, antidotes, 631 

in local anesthesia. See Anesthesia, 

local . 
Meyer's compound high pressure 

syringe, 401 
pressure anesthesia with, 401 
for pulp anesthesia. See Anesthesia, 

pulp, 
syncope, treatment, 400 
Contact points, 153 

in gold fillings, 218, 230 
in lateral incisors, 28 
in upper central incisors, 25 
cuspids, 32 
Contouring apparatus for dento-facial 

imperfections, 903 
Cotton, removal of old root canal filling, 
431 
rolls, absorbent and non-absorbent, 
use of, 199 
Crown- and bridge-work, extirpation of 

healthy pulps for, 391 
Crowns, gold, as cause of pyorrhea, 473 
removing gutta-percha set, 317 
setting with gutta-percha, 313 
source of infection, 124 
Cuspids, deciduous, 52 
fillings in, 34 
odontograph}-, 23, 30 
the upper, 30 
Cusps, evolution, 18 
Cysts, peri-apical, treatment, 452 



Deciduous teeth, abscess on, 453 
alveolar, 681 

chronic, root canal fillings 
for, 462 
duration, 666 
effect of candy, 682 
extraction, 586 
filling, amalgam, 676 

application of rubber dam, 

673 
cement, 675 

Ames' copper, 673 
cavity preparation, 675 
protecting filling with 

paraffin, 676 
zinc phosphate, 673 
Gilbert's temporary stop- 
ping, 676 
gutta-percha, 312, 670 

advantages and disad- 
vantages, 673 
Hollingsworth space 

guard. 672 
occlusal cavities, 670 
proximal cavities, 672 
incisor cavities, 676 
materials, 331 
pulp protection, 675 
tin, 678 

and gold, 678 
gum lancing to facilitate erup- 
tion, 664 
indications, 665 
technique of operation, 
665 
management, 664 
odontography, 51 
premature loss as cause of mal- 
occlusion, 721 
prolonged retention a cause of 

malocclusion, 724 
prophylactic treatment, 682 
pulp canal filling, 680 

aqua ammonise in, 680 
devitalization and ex- 
tirpation, 678 
devitalizing paste, 679 
mummifying paste, 680 
occlusal cavities, 679 
proximal cavities, 697 
salol in, 681 
reasons for preservation, 666 
root canal fillings, 462 
treatment of caries with silver 
nitrate, 669 
of odontalgia, 668 
Deformities. See Dento-facial Imperfec- 
tions; also Malocclusion. 
Dehydration of dentin, 146 
Dentin, anesthesia by pressure, 642 
chemical analysis, 8 
dehydration, 146 
desiccation, 146 
exposed, silver nitrate for, 151 
formation of secondary, 145 
granular layer of Tomes, 87 



920 



INDEX 



Dentin, histological description, 83 
interglobular spaces, 88 
in root, 85 
secondary, 89 
sensitive, 145 

anesthesia, 401 
medication, topical, 148 
carbolic acid, 151 
cataphoresis, 148 
cauterants, 151 
coctiin analgesia with press- 
ure syringe, 148 
hydrochloric!, 148 
ether or ethyl chlorid, 148 
hot water, 148 
injecting cocain into gum 

tissues, 149 
Robinson's remedy, 151 
silver nitrate, 151 
vapocain, 148 
zinc chlorid, 151 
pulp extirpation in, 391 
treatment, 46 

under general anesthesia, 

150 
under partial ether anes- 
thesia, 150 
by temporary filling, 151 
sheaths of Neumann, 84 
structure, 82 
Dentinal tubules, 83 

direction, 84 
Dentition, pathological complications, 

664 
Dento-enamel junction, 87 
Dento-facial imperfections, 873 
causes, 873 
local, 873 
physiological, 874 

eruption of teeth, 874 
irregularities of teeth, 876 
naso-maxillary sinus dis- 
ease, 876 
diagnosis, 878 
protrusions, upper, 881 
treatment, 881 

by extraction, 881 
by "jumping the bite," 882 
retruded and contracted dental and 
maxillary arch, 889 
treatment, 889 

contouring apparatus, 903 
upper incisors and intermaxil- 
lary process, 888 
retrusions, upper dental and maxil- 
lary, 887 
Dentures, artificial, extraction of sound 

teeth preparatory to inserting, 546 
Deposits on teeth, removal of, 135 - 
Desiccation on dentin, 146 
Development of tooth forms, 18 
Diphtheria, auto-infection, 125 
Discoloration of teeth, 428, 519 
chemical processes, 520 
from death of exposed pulp, 523 
from metallic salts, 542 
from pulp removal, 405 
treatment, 524 See also Bleaching. 



Discolored teeth, cement lining for fill- 
ings in, 329 

Disinfectant, definition, 128 

Disks for cavity preparation, 164 

Division of food, 17 

Dolichocephalic peoples, type of dental 
arch in, 20 



Electric mallet, 213 
Elevators for extracting roots, 558 
Empyema of antrum, 439, 451 
Enamel, brown bands of Retzius, 69 
chemical composition, 61 
incremental lines, 70 
manner of cutting, 62, 66 
origin, 59 
rods, direction, 68 
sections, action of acids on, 61 
stratification bands, 69 
striations, 63 
structure, 61, 63 

walls, histological requirements for 
strength, 71 
Engine mallet, 214 
Entoconid, 19 
Eruption of teeth, changes of peridental 

membrane, 117 
Escharotics, carbolic acid, 127 

zinc chlorid, 127 
Ether for general anesthesia. See Anes- 
thesia. 
for partial anesthesia, 150 

apparatus for administration, 
150 
spray, for obtunding sensitive den- 
tin, 148 
Ethyl chlorid for local anesthesia. See 
Anesthesia, 
spray for obtunding sensitive den- 
tin, 148 
Eucalypto-percha for root canal filling, 

457 
Euca-percha for root canal filling, 457 
Evolution of tooth forms, 18 
Examination of teeth and oral cavity 
preliminary to operation, 135 
technique, 138 
Excavating cavities. See Dentin. 
Excavators for cavity preparation, 157 
contra-angled, 160 
formulae for, 159 
hatchets, 159 
hoes, 169 
spoon-shaped, 160 
sterilization, 120 
Expansion arches, Angle's, 743 
Exploring instruments, 136 
Extraction of teeth, 545 
accidents, 606 
after subperiosteal injection of local 

anesthetic, 637 
after-treatment, 605 

under anesthesia. See Anesthe- 
sia. 



antisepsis important, 126 



INDEX 



921 



Extraction, antiseptic precautions, 122 
deciduous, 386 
general principles for, 579 
hemorrhage, control, 607 
impacted lower third molars, 602 

complications, 604 
indications for, 545 
infection through, 125 
injudicious, effect on facial lines, 

719 
instruments and accessories, 548 
elevators, 558 

manner of using, 582 
forceps, 548 
joints, 549 
for lower teeth, 553 
manner of using, 583 
selection of, 550 
for upper teeth, 550 
lancets, 559 

mechanical mouth-opener, 560 
mouth props, 559 
osteotome, Oyer's, 603 
pharyngeal forceps, 560 
root extractors, 558 
scissors, 559 
selection and use, 581 
lancing, 583 

malformed and abnormally placed 
teeth, 595, 602 
diagnosis by radiograph, 596 
malocclusion produced by, 708 
molar, first, serious consequences of, 

830 
mutilation, treatment following, 

828 
necrosis, alveolar, following, 453 
permanent lower, anterior teeth, 
591 
bicuspids, 592 
molars, first, 593 

effects of, 21 
second, 594 
third, 594 
permanent upper, bicuspids, 5S8 
canines, 588 
central incisors, 587 
lateral incisors, 588 
molars, first and second, 589 
third, 590 
physiognomy, relation to the saving 

and, 893 
position of operator, 581 

of patient, 580 
in protrusion, upper, 886 
of roots w r ith elevators, 581 
sound teeth preparatory to artificial 

dentures, 546 
surgical anatomy, 561 

abnormalities in position of 

teeth, 578 
alveolar process, 561 
bicuspids, second, 567 
impacted third molars, 573 
in negroes, 566 
relation of teeth to internal 

structure of jaws, 565 
root forms, 565, 568 



Face, fistulse on, treatment, 451 

restoration to symmetry by ortho- 
dontic treatment, 717 
Facial art, 709 

scar, depression of, treatment, 451 
Fibroblasts, 104 

Files for finishing gold fillings, 231 
Fillings in bicuspids, lower, 50 
upper, 49 
for cavities in enamel, 71 
combination, 324 
in cuspids, 34 

in deciduous teeth, amalgam, 676. 
See also Deciduous teeth, 
gold, 678 m 

and tin, 678 
tin, 678 
of glass. See Inlays, 
of gold, finishing, 228. See also Gold, 
instruments for, 230 
repairing, 232 
m starting, 217, 219, 221, 223, 225 
in incisors, 24 
manner of inserting material with 

matrix, 242 
materials, advantages and disadvan- 
tages, 324 
for anterior teeth, selection of, 

329 
selection of, 201 
of metal, causing pulp irritation, 392 
in molars, lower, 50 

upper, 50 
porcelain rod. See Inlays, 
root canals. See Root canals, 
separation preparatory to, 140 
temporary, gutta-percha, 312 
of tin, 226 
Fissures, occlusal, cutting out in bi- 
cuspids and molars, 72 
Fistulse, in antrum of Highmore, treat- 
ment, 451 
on the face, treatment, 451 
in pyorrhea alveolaris, 500 
treatment, 448 
Food, division, 17 
insalivation, 17 
mastication, 17 
prehension, 17 

soft, cause of dental irregularities, 
725 
Forceps for extracting, 548 
infection through, 126 
sterilization, 122 
Formaldehyd, investigations on germi- 
cidal power, 129 
for putrescent pulp treatment, 429 
lamps, 129 
Formalin as sterilizing agent, 134 
Formocresol for putrescent pulp treat- 
ment, 422, 430 
Formopercha for root canal filling, 457 
Fossa, definition, 173 
Frenum labiorum, abnormal, cause of 

malocclusion, 725 
Fumigation, 130 



922 



INDEX 



Function of teeth, 17 
Furnaces, coke, old style, 362 
electric, Custer's, 362 
Hammond's, 362 
Pelton's, 364 
White's, 363 
gas, Land's, 362 
gasoline, Brophy's, 364 
Turner's, 364 



G 



Gangrene. See Pulp gangrene. 
Germicide, definition, 128 
Gingivitis. See Pyorrhea alveolaris. 
Glass inlays, 334 
Glasses, sterilization, 121 
Gold, adapting to cavity walls, technique, 
209 
and amalgam fillings, 329 
versus amalgam fillings, 325 
annealing, 208 
automatic pluggers, 211 
for casting, 380 
casting to other pieces, 481. See 

also Inlays, cast gold, 
and cement fillings, 328 
cohesive, indications for, 238 

objections to, 237 
condensers, 210 
crystal, 207 
electric mallet, 213 
engine mallet, 214 
for filling, 201 

fillings, cement lining for, 329 
by classes, 217 

proximal surface cavities of 
bicuspids and molars, 221 
proximal surface cavities of 
incisors and cuspids in- 
volving incisal angle, 220 
proximal surface cavities of 
incisors and cuspids not 
involving incisal angle, 
218 
small cavities in occlusal 
surfaces of bicuspids and 
molars, 224 
smooth surface cavities in 
gingival third of labial, 
buccal, and lingual sur- 
faces, 217 
cohesive and non-cohesive, fill- 
ing proximal cavities with 
anterior teeth matrix, 258 
contact points, 218, 230 
finishing, 228 

with burs, 228 
instruments for, 229 
files, 231 
knives, 231 
with points, corundum, 228 
Hindostan, 229 
wood, 228 
matrices for. See Matrices, 
with matrix, finishing, 249 

manner of introduction, 242 



Gold fillings with matrix, pluggers for, 
259 
in proximal surfaces of bi- 
cuspids and molars, 224 
repairing, 232 

with amalgam, 233 
in fracture of walls, 233 
with gutta-percha, 233 
starting, 217, 219, 221, 223, 225 
foil, cohesive, 205 

action of gases on, 205 
advantages, 205 
formation of cushions from, 
248 
soft or non-cohesive, 202 
cylinders, 204 
mats, 203 
rolls, 204 
tape, 203 
inlays. See Inlays, 
introduction of, 209 
moss fiber, 207 
and platinum, 208 
plugger points, 216 
plugging instruments, 210 
preparation for matrix fillings, 246 
puritv required, 202 
and tin fillings, 239, 249, 321 
trimmers, Rhein's, 249 
Gum lancing, antiseptic precautions, 121 
to facilitate eruption of decidu- 
ous teeth, 664 
Gutta-percha, 309 

and cement fillings, 330 
chemical changes in, 311 
classes, 311 

combined with other materials, 318 
decay in the mouth, 313 
fillings, cavity preparation, 314 
in deciduous teeth, 670 

Hollingsworth's space- 
guard in, 672 
finishing, 316 
instruments, 317 
trimmers, 316 
and gum shellac, 318 
heaters, 314 
Hill's stopping, 310 
hot-air syringe for softening, 317 
indications for employment, 312 
manipulation, 314 
with medicinal agents, 318 
physical properties, 311 
for repairing filings, 233 
for root canal filling, 456 

removal of old, 431 
and rubber, properties, 310 
temporary stopping, 318 



Habits, pernicious, cause of malocclu- 
sion, 724 

Hand-pieces, sterilization, 121 

Hands, preparation previous to opera- 
ting, 133 

Headgear in orthodontia, 750 



INDEX 



923 



Hemophiliacs, systemic treatment, 609 
Hemorrhage, control after extraction, 607 

local, 607 

after pulp removal, 400 

systemic, 609 
Herbivora, tooth forms in, 24, 34 
Histology, dental, 56 
Howship's lacuna?, 96, 110 
Hydrogen dioxid for bleaching teeth, 534 
danger of use in abscess treat- 
ment, 442, 448 
Hydronaphthol for sterilizing instru- 
ments, 132 
Hygiene, oral, 123, 910 

necessity in public schools, 125 
Hypocone, 18 
Hypoconulid, 19 



Impaction of teeth, 573, 595 
canines, 588, 597 
disturbances due to, 600 
extracting operation, choice of, 602 
frequency, order of, 595 
third molar, 573, 595 
Implantation of teeth, precautions, 127, 
655. See also Plantation, 
technique of operation, 658 
incision, 659 
instruments, 660 
preparing sockets, 660 
terminology, 646 
Impression material for orthodontia 
models, 733 
trays, 734 
Incisors, cervix, 24 

choice of fillings, 24 
cingulum, 24 
deciduous, 51 
lateral, 26 
lower, 29 
odontography, 23 
tubercles, 25 
upper central, 24 
retruded, 888 
Incremental lines in enamel, 70 
Infection, caution against, 122 
external, 126 
through the mouth, 118 
from mouth to mouth, 125 
from oral bacteria, 123 
oral, bridge-work a source of, 124 
crowns a source of, 124 
through extraction, 125 
vaccine therapy in, 509 
of pulp, dangers, 123 
Inflammation from bacterial invasion 
around lower third molars, 124 
gingival, due to faulty crowns, 124 

due to neglect of antisepsis, 123 
peridental, due to faulty crowns, 

124 
from rubber dam, 120 
Infra-occlusion, treatment, 825 
Inlays, advantages, 335 
amalgam, 327, 331 



Inlays, cavity preparation for pit and 
fissure cavities, 166 
cement for, 301 
cemented, restoration of teeth by, 

333 
glass, 334 

Land's matrices for, 334 
gold, 364 

Alexander's method of making, 

384 
cast, 367. See also Casting, 
cavity preparation, 335 

in bicuspids and 
molars, 345 
finishing, 371 
impression and die method for, 

388 
investments for, 374, 384 
mixing, 375 

Ritter mixer, 378 
Taggart's mixers, 375 
selection of gold, 380 
setting, 371 

wax model for, 345. See also 

Wax. 

burning out the wax, 

379 

Taggart's au- 

tomatie ap- 

paratus,379 

carving with Roach's 

suction carver, 346 
investing, 369, 376 
making, 367 
mounting on sprue 
wire, 369 
matrix, 364 

incisal tips on anterior 

teeth, 366 
indications for, 365 
method of building up with 
blowpipe, 366 
of making matrix, 366 
Rowan's decimal gold for, 
366 
versus porcelain, 336 
impression and die method, advan- 
tages, 387 
models of amalgam, method of 

making, 387 
in molars, upper, 50 
porcelain, baking, 350 

cavity preparation, 335 

abrasion or erosion cavi- 
ties, 337 
in bicuspids, 343 
gingival, extending under 

gum margin, 341 
incisal, 340, 342 
labial, 338 
in molars, 343 
proximal, 339, 342 
simple, 336 
cements and manipulation for 

setting, 357 
furnaces, 362 
fusing, 359 

electric current in, 360 



924 



INDEX 



Inlays, porcelain, fusing, pyrometer for, 
359 
ground rod, 333 
hydrofluoric acid for roughening 

cavity surface, 352 
impression and die method for, 

387 
low fusing, 353 
baking, 356 

building up the porcelain, 
356 
corners, 357 
gold matrix for, 353 

making with wax 
form, 355 
instruments, for manipu- 
lating porcelain 
paste, 353 
for shaping matrix, 353 
matrices for, 335 

filling matrix, 349 
forming, 347 

with burnishers, ball- 
pointed, 348 
Reeves', 350 
Sausser's, 351 
platinum foil for, 348 
removing from finished in- 
lay, 352 
trimming after first fusing, 
351 
mixing the porcelain, 349 
rod, How's burs for, 333 

Weagant's instruments, 333 
selecting shades, 351 
setting, 352, 357 
shading, 357 
shrinking, 350 
staple anchorage for, 342 
swaging process in making, 386 
varieties of material for, 360 
Brewster press, 388 
materials, 389 
Insalivation of food, 17 
Insectivora, tooth forms in, 18 
Instruments for bleaching teeth with 
chlorin, 531 
extracting, 548 
implanting teeth, 661 
orthodontia. See Orthodontia tools, 
plugging gold, 210 
scaling teeth, 486 

sterilization, by boiling in water and 
soda, 131 
formaldehyd, 130 
Interdental spaces, creating, preparatory 

to filling, 140 
Interglobular spaces, 88 
Intermaxillary process, retruded, 888 
Iodin for bleaching teeth, 534 

in treating pyorrhea alveolaris, 489 
Iodoformagen for pulp capping, 394 
Iodoglycerol in treating pyorrhea alveo- 
laris, 492 
Irregularities, 881. See Dento-facial im- 
perfections. 
of teeth. See Malocclusion; also 
Orthodontia. 



Knives for finishing gold fillings, 231 



Lactic acid in scaling teeth, 491 

Lancets, 559 

sterilization, 121 

Lancing gums, 121 

Lead for fillings, 201 

Lips in dento-facial imperfections 880 
pressure in occlusion, 696 
retrusion of entire upper lip, 888 
sucking, a cause of malocclusion. 
724 

Lobes in incisors, three, 24 



M 



Magnifying glass, 137 
Malformation and malposition of teeth, 
diagnosis before extracting, 595 
disturbances due to, 600 
Mallets, automatic. Abbott's, 213 
Foote's, 211 
Salmon's, 213 
Snow and Lewis', 211 
electric, Bonwill's, 213 
mechanical engine, Bonwill's, 214 
Buckingham's, 216 
Homes', 216 
Malnutrition, relationship to pyorrhea 

alveolaris, 502 
Malocclusion, absence of teeth, partial, 
718 
Angle's classification, 701 
brief summary, 708 
nomenclature, 701 
definition, 683 
etiology, 721 

abnormal frenum labiorum, 725 
disuse of teeth, 725 
enlarged faucial tonsils, 721 
loss of permanent teeth, 724 
pernicious habits, 725 
premature loss of deciduous 

teeth, 721 
prolonged retention of deciduous 

teeth, 724 
supernumerary teeth, 724 
tardy eruption of permanent 
teeth, 724 
from extraction, 708, 719 
forces governing, 697 
arches, 697 
lips, 697 

malposition of teeth, 698 
mouth-breathing, 699 
stress, 700 
tongue, 699 
face, effects on beauty of, 709 
facial asymmetry, as cause of, 714 
examples of the various classes, 
715 
infra-occlusion, treatment, 825 



INDEX 



925 



Malocclusion, proportion of occurrences 
of types, 709 
treatment. See Orthodontia. 
Malposition of teeth, producing mal- 
occlusion, 698 
Mammals, teeth in, 17, 23, 34 
Margins, formation in enamel, 75 
Mastication, dynamics of, 21 
of food, 17 
occlusion in, 21 
Matrices, for anterior teeth, 256 

filling proximal cavities with 
gold, 258 
auxiliary, 261 

contour, for molars and bicuspids, 
Crenshaw's, 255 
Hodson's, 254 
forms, for molars and bicuspids, 250 
Brophy's, 250 
Crenshaw's, 253 
Guilford's, 251 
Hewett's, 252 
Jack's, 259 
Lodge's, 252 
'Woodward's, 251 
general considerations, 235 
in gold fillings in proximal cavities 
of anterior teeth, 258 
surfaces in bicuspids 
and molars, 224 
indications for, 238 
selection of, 236 
Matrix work, cavity preparation of the 
major class for, 239 
of the minor class for, 
244 
manner of inserting filling, 242 
pluggers for, 259 
Maxillary bones, influence of teeth on 
development of, 873 
retrusion, 887 
Membrana eboris, 90 
Mercury, as solvent for metals, 263. Sec 

also Amalgams. 
Models in orthodontia, 733 

plane for, 737 
Moisture, exclusion of, 191 
Molars, deciduous, 52 

reasons for preserving, 666 
first permanent, as key to occlusion 
689 m 
extraction, serious conse- 
quences, 830 
fourth, 49 ' 

impacted third, surgical anatomy, 
573 
extraction, 590, 595, 602 
lower first, 44 
second, 46 
third, 48 

inflammation around, due 
to bacterial invasion, 124 
odontography, 23, 39 
phylogenesis, 18 
triangles of, 18 
upper, 40 
first, 41 
second, 43 



Molars, upper, third, 47 
Morphin, idiosyncrasies to, 441 
Mouth mirrors, 137 
electric, 139 

props, 559 
Mouth-breathing in malocclusion, 699 
Mucous membrane, infection, 124 
Mummification of pulp, 462 

in deciduous teeth, 680 
Myeloplaques in peridental membrane, 
110 



N 



Napkins, aseptic, 199 
sterilization, 121 
use with rubber dam, 198 
Nasmyth's membrane, 115 
Nausea from rubber dam, 200 
Necrosis and caries of bone, due to ab- 
scess or extraction, 453 
following extraction, 125 
Negroes, anatomical considerations in 

extracting teeth of, 566 
Neumann, sheaths of, 84 
Nickel silver for regulating appliances, 

741 
Nitrous oxid for general anesthesia. See 

Anesthesia. 
Nose in dento-facial imperfections, 880 
Novocain in local anesthesia. See Anes- 
thesia. 



Occlusion of the teeth, 20 
Bon will's "law," 693 
definition, 683 

effect on facial symmetry, 714 
forces governing normal, 695 
arches, 695 
lips, 696 
importance of first permanent molar, 
689 
in filling technique, 154 
key to, 689 
line of, 692 
normal, 684 

relationship of individual teeth, 684 
Odontalgia, See Toothache. 
Odontoblastic cells, 89 

processes, 90 
Odontography, 17 

Operative appliances and methods, 135 
Opsonic index, method of determining, 

514 
Opsonins and opsonic index, 512 
Oral prophylaxis, 910 
Orthodontia, 683. See also Dento-facial 
orthopedia, Malocclusion, Occlu- 
sion, 
adjustment and operation of appli- 
ances. See Regulating appliances, 
anchorage, 764 
Baker's, 768 
details, 765 



920 



IXDEX 



Orthodontia, anchorage, intermaxillary, 

767 
combinations for, 780 
occipital, 767 
principles, 764 
reciprocal, 766 
simple, 766 
stationary, 766 
Angle's classification of malocclu- 
sion, 701 
brief summary, 708 
bands, 757 

attaching spurs, staples, and 

tubes, 761 
for canines, 763 
fitting, 760 
soldering, 760 
definition, 6S3 

extraction contraindicated, 719 
forces applied in regulating, 765 
impressions, material for, 733 
method of taking, 734 
lower, 736 
upper, 735 
trays, 734 
varnishing, 736 
models, 733 

plane for, 737 

pouring and separating, 737 
photographs for records, 738 
principle of facial symmetry, 710 
regulating appliances. See Regula- 
ting appliances, 
retention. See Retention. 
Rontgenographs for diagnosis, 738 
soldering, 757 

soft-soldering sheath-hooks and 

spurs, 763 
tube to band, 759 
tissue changes during retention, 799 
tools, 753 

band driver, 755 
blowpipe, 755 
Griinberg's holder, 757 
hand mallet, 755 
Oppenheim's holder, 755 
pliers, 753 

bandforming, 754 
How's, 755 
regulating, 753 
soldering, 753 
scissors, 755 
wire-cutters, 755 
wrenches, 755 
tooth movement, alveolar process, 
and peridental membrane in. 
726 
physiological changes subse- 
quent to, 730 
in alveolar process, 730 
in the teeth, 730 
pulp in, 729 

tissue changes incident to, 726 
in depressing a tooth, 

727 
in elevating a tooth, 

727 
in moving teeth, 728 



Orthodontia, tooth, tissue changes in 
rotating teeth, 728 
treatment, 808 

cases of Class 1, 810 

arch widening and nar- 
rowing, 812 
infra-occlusion, 825 
mutilation by extrac- 
tion, 828 
cases of Class II, Division 1, 834 
anchorage, intermaxil- 
lary, 851 
molar and occipi- 
tal, 851 
appliances for retract- 
ing incisors and ca- 
nines, 851 
arrested growth of man- 
dible, 845 
extraction of first upper 
premolars contrain- 
dicated, 850 
Kingsley's method, 850 
"jumping the 
bite," 853 
minimizing pain, 846 
regulating, technique, 

838 > 
retention, 843 
cases of Class II, Division 1, 

subdivision, 856 
cases of Class II, Division 2, 857 

vulcanite plates, 861 
cases of Class II, Division 2, 

subdivision, 862 
cases of Class III, 864 
appliances, 867 
early treatment impor- 
tant, 864 
f aucial tonsils, 866 
resection of the jaw, 
double, 871 
cases of Class III, subdivision, 

871 
importance of early interven- 
tion, 733 
preliminary considerations, 808 
and rhinology, cooperation of, 701 
Orthodontist, art study for, 709 
Orthopedia, contouring apparatus, 903 
anchorage, 905 
apparatus for retruding roots 

of teeth, 908 
bending pliers, 909 
power bows, 905 
treatment adjustments, 907 
dento-facial, 873 
principles, 879 

relations of physiognomy to saving 

and extraction of teeth, 893 

Osmosis, electric, for sensitive dentin, 148 

Osteoblasts in peridental membrane, 108 

Osteoclasts in peridental membrane 110 



Pacifier, a cause of malocclusion, 724 
Pain, referred in pulps, 93 



INDEX 



927 



Paracone, 18 

Paraffin for root canal filling, 458 
Perforation. See Root canal. 
Perhydrol for bleaching teeth, 535 
Pericemental tissue, hypertrophy, treat- 
ment, 455 
Pericementitis, apical, treatment, 431 
from neglect of antisepsis, 123 
non-septic, treatment, 454 
rubber dam guard in, 440 
suppurative, causes, 432 
Pericementum, 59, 97 
Peridental membrane, 59, 97 
Black's " glands, "495 
bloodvessels, 117 
cellular elements, 104 
cementoblasts, 105 
changes with age, 117 
epithelial structure, 111 
fibers, 100 
functions, 98, 104 
nerves, 117 
in orthodontia, 726 
osteoblasts in, 108 
osteoclasts in, 110 
so-called ''glands" of, 113 
structural elements, 98 
Periosteum, dental, 97 
Phenolsulphonic acid for abscessed teeth, 

448 
Phylogenesis of molars in man, 19 
Physiognomy, influence of teeth, 873. 
See also Orthopedia, facial, and 
Dento-facial imperfections, 
relations to saving and extraction of 
teeth, 893 
Pins, removal from root canals, 432 
Plantation of teeth, 646 
anesthesia, 658 
artificial crowns, 656 

roots, 654 
asepsis, 656 

biological conditions, 647 
care of planted teeth, 653 
retention cap, 653 
stimulation of gum, 654 
history, 646 

mode of attachment, 654 
precautions, 655 
preparation of teeth for, 651 
pericementum, 652 
root filling, 652 
scion tooth, 651 
resorption of roots, 663 
technique of operation, 658 
instruments, 660 
Plastics, 262 
Plates. See Dentures. 
Platinum, behavior in casting, 380 

and gold in fillings, 208 
Pluggers for amalgam, 282 
Bing's, 210 
for matrix work, 259 
points, 216 

Chappell's, 217 
Varney's, 217 
Webb's, 217 
Points, for cavity preparation, 164 



Points, corundum for finishing gold fill- 
ings, 228 
Hindostan, 229 
wood, 228 
Polishing points, wood, for gold fillings, 

228 
Porcelain cavity stoppers, 334 

comparative fusing points, 362 
furnaces, 362 

high fusing versus low fusing, 361 
for inlays, varieties of, 360 
inlay for labial surface, 218 
low fusing. See Inlays, 
rod inlays, 333 
Prehension of food, 17 
Premolars, odontography, 23, 35 
Prophylactic treatment of deciduous 

teeth, 682 
Prophylaxis, oral, 123, 910 
Protocone, 18 
Protrusions, upper, 881 
Public schools, necessity of oral hygiene 

in, 125 
Pulp, 89 

abscess, 395 

anesthesia, aids in difficult cases, 403 
by adrenalin and formaldehyd 

pressure, 400 
by carbolic acid and cocain 

pressure, 403 
by cocain-adrenalin injection, 

404 
by cocain cataphoresis, 403 
by cocain pressure, 399 
by high pressure syringe, den- 
tinal, 402 
methods, 399, 643 
by nervocidine, 403 

Soderberg's improved 

method, 403 
presGure, 642 
bloodvessels, 93 
canals, in bicuspids, lower, 39 
upper, 36 
in canines, lower, 33 

upper, 32 
in incisors, lower central, 30 
upper central, 26 
lateral, 28 
in molars, deciduous, 53 
lower first, 46 
second, 47 
third, 49 
upper first, 43 
second, 43 
third, 48 
capping, 394 

contraindications, 393 
medicated cements for, 394 
chamber, opening into, 411 
dangers from infection, 123 
death of, causing discoloration, 519 

spontaneous, 425 
devitalization, accidents from arsen- 
ical applications, 408 
allaying pain from arsenic dress- 
ing, 407 
arsenic, 404 



928 



INDEX 



Pulp devitalization in deciduous teeth, 
409, 678 
in fractured teeth, 408 
objections to arsenic, 405 
sealing the arsenic, 406 
devitalizing fiber, 406 

paste, 406 
digestion, Harlan's paste for, 463 
exposure, cement for, 314 
extirpation, 410 

under anesthesia, general, 399 
anesthetizing apical remnants, 

408 
antiseptic precautions, 415 
broaches for, 412 
of healthy, covered with suffi- 
cient dentin, 391 
hemorrhage, treatment, 400 
removal of debris, 415 
root-canal dressing after, 401 
special methods of preparing for, 

408 
of vital, covered with sensitive 
m dentin, 391 
functions, 93 
sensory, 93 
vital, 93 
gangrene, 395 
dry, 425 
moist, 426 

without pericementitis, 426. 
See also Pulp, putrefac- 
tion, 
treatment, 429 
histological description, 89 
hyperemia, causes, 392 
hyperplasia, treatment, 398 
infection, by way of apical tissue, 397 
by way of blood stream, 398 

of dentin, 394 
in pyorrhea, 398 
pathology, 395 
irritation, from arsenic in cements, 
301 
from large metal fillings, 392 
mummification, 425, 462 
of root portion, 461 
nerves, 93 

nodules, treatment, 403 
pain, referred in, 93 
protection, gutta-percha for, 312 
putrefaction, 426 

etiology and pathology, 426 
symptomatology, 428 
treatment, 429 
putrescent, reaction to hot and cold, 

395 
spontaneous death of, 425 
in tooth movement, 729 
treatment, when dead, 42 

dry gangrene, 425. See 
also Root canal treatm ent . 
mummifying pastes, 425 
ulceration, 396 

vital, exposed, indications for preser- 
vation, 393 
Jack's reactions to cold and hot, 
395 



Pulp, vital, treatment of recently ex- 
posed, 392 
septic, treatment, 395 
Pulpitis, chronic, pathology, 428 
Pyorrhea alveolaris, abscesses and fis- 
tulse in, 501 
antiseptic drugs for, 503 
bismuth paste, 503 
silver iodid, 503 
of arthritic type, 502 
bacterial infection in, 495 
constitutional predisposition, 494 

predisposing factors, 504 
definition, 464 
destruction of alveolar bony tissue, 

498 
diagnosis, differential, 500 
from scorbutus, 500 
from specific infections, 500 
from Vincent's angina, 500 
epithelial remnants in peridental 
membrane as source of infection, 
496 
etiology, 471 

external factors, 472 
bacteria, 472 
mechanical injury, 472 
tartar as a predisposing 
cause, 473 
general considerations, 469 
history, 464 

inflammatory nature, 469 
medical cooperation in systemic 

treatment, 508 
from neglect of antisepsis, 123 
from nutritional disorders, 494 
opsonins and opsonic index in, 512 
"pen" for medicinal applications, 

507 
pericemental abscess, 500 
pneumococcus in, 495 
prognosis, 509 
pulp infection, 398 
pus, bacteriological examination of. 
502 
pockets, 500 
radiograph, a valuable diagnostic 

aid, 503 
relationship to malnutrition, 502 
scaling, after-treatment, 492 _ 

Black's preparation, 

493 
iodoglycerol, 492 
quinin sulfate, 493 
Younger's preparation, 
491 
zinc chlorid, 493 
asepsis in, 489 
chemical aids in, 491 

Head's "Tartasol," 492 
cocain in, 491 
contraindications to, 505 
hemorrhage, control of, 490 
hot air in, 490 
instruments, 486 

dentate scalers, 488 
handles, selection of, 486 
temper, 486 



IXDEX 



929 



Pyorrhea, scaling instruments, types, 
486 
novocain in, 491 
pain, control of, 490 
preparatory details, 489 
serumal tartar in, 503 
splinting loose teeth, 507 
terminology, 468 
theories, early American, on, 466 

French, on, 464 
treatment, 486 
iodin, 489 

removal of deposits, 4S9 
systemic, 505 
vaccines, 509 
uratic deposits in, 503 
vaccines in, 509 

method of inoculation. 517 
Pyrozone, for bleaching teeth, 535 



R 



Radiograph diagnosis in chronic apical 
abscess, 449 
in malformed and malplaced 

teeth. 596 
in orthodontia, 738 
in pyorrhea alveolaris, 503 
Record charts, 136 

keeping, advantages, 139 
Regulating appliances, 739 

adjustment and operation, 768 
Angle's, 742 

chin retractor, 752 
clamp-bands, 745 
expansion arches, 743 
plain, 743 
ribbed, 744 
threadless, 745 
headgear, 750 
jack-screws, 749 
ligature wire, brass, 747 
retaining tubes, 747 
rubber strips, 747 
sheath-hooks, 745 
spring levers, 750 
traction bar, 750 
screws, 749 
clamp-bands, 770 
cementing, 771 
gaining space for, 772 
mistakes, 7?1 
.-heaths, 772 
combination adjusted, 775 
plain arch, 777 
notched arch, 777 
combination for intermaxillary 

anchorage, 780 
combinations, miscellaneous, 782 
double rotation, 787 
drawing tooth into line of 

occlusion, 788 
jackscrews, 786 
levers, 787 
in relapses, 787 
traction screws, 782 
in canines, 782 
59 



Regulating appliances, combinations, 
traction in premo- 
lars, 785 
in shortening lateral 
half of arch, 785 
widening distance between 
deciduous canines, 788 
expansion arch, 769, 774 
reinforced, 781 
gradual adjustment, 779 
individual, 739 
materials for construction, 741 
plain bands, 773 
ready-made, 740 
for retention. See Retention, 
soldering, 757 
teeth. See Orthodontia, 
wire ligatures, 774 
forms of, 775 
Replantation of abscessed teeth, 450 

of teeth, antiseptic precautions, 127. 

See also Plantation, 
indications for, 649 
technique, 649 
terminology, 646 
Resorption of roots of permanent teeth, 

treatment, 456 

Retention in orthodontia, 789 

cases of Class I, 791 

cases of Class II, 803 

canines, 806 

incisors, 807 

intermaxillary retainers, S03 
Griinberg's modification, 
805 
lingual arch for maintaining 

width, 805 
molars, 807 
plates for maintaining width, 

806 
spurs, set in fillings, 805 
cases of Class III, 807 
permanent devices, 792 

for aligning canines, 796 
incisors, 794 

Bunker's device, 795 
bands and spurs, 793 
lingual arch, 789 
for molars, 797 
plates, 797 

for rotated incisors, 793 
section wires, for preserving 

space, 793 
spurs, 793 

working retainer, 800 
principles, 790 
temporary devices, 791 . 
time required, 789 
Retrusions, upper dental and maxillary, 

887 
Retzius, brown bands of, 69 
Rhinology and orthodontia, cooperation 

of, 701 
Riggs' disease. See Pyorrhea alveolaris. 
Robinson's remedy for sensitive dentin, 

151 
Rollins' tubular knife for abscess treat- 
ment, 442 



930 



INDEX 



Root, apex, amputation of, 449 
canals, 391. See also Pulp, 
abnormal shapes of, 420 
cleaning, 411 

antiseptic precautions, 415 
in bicuspids, 413 
Kerr's reamers for, 413 
lactic acid for, 413, 424 
in molars, 413 
in single-rooted teeth, 413 
sodium potassium for, 414, 424 
sulfuric acid for, 413, 424 
dressing, manner of manipulating 
broaches, 459 
after pulp removal, 401 
temporary germicidal, 457 
filling of, 456 

for bleached teeth, 529, 533 
broaches for, 459 
Canada balsam, 548 
chloropercha, 457 
cotton and chloropercha, 459 
and zinc oxychlorid, 459 
covering for, 462 
in deciduous teeth, 462, 680 
embalming paste, 457, 461 
eucalypto-percha, 457 
floss silk and chloropercha, 459 
gutta-percha, 312, 456 

cones, manner of fitting, 460 
immediate, paste for, 401 
with inaccessible apices, 461 
measuring length of root to be 

filled, 460 
normal, tapering, well-opened, 

459 
with open foramina, 460 
paraffin, 458 

pulp digestion preceding, 463 
Rhein's mummifying method, 

461 
removal of old, 431 
salol, 458 
Soderberg's mummifving paste, 

461, 463 
wax, 458 

zinc ox3 r chlorid, 457 
normal shapes of, 416 
opening, accidents in, 424 
perforation of, 424 

filling, 455 
removal of broken instruments from, 

424 
restoring lost continuity of, 423 
treatment, 415 

in bleaching teeth, 530 
cement for sealing dressings, 314 
fine and tortuous canals, 421 
formocresol, 422, 430 
gutta-percha for sealing dress- 
ings, 313 
with vital pulps, 391 
widening, Gates-Glidden drills for, 
414 
Kerr's reamers for, 413 
Roots, extracting with elevator, 581 

relation to internal structures of jaw, 
565 



Roots, various forms of, 565, 568 
Rubber cup for abscessed gums, 448 
dam, antiseptic application, 120 

application in filling deciduous 
teeth, 673 

arrangement on face, 197 

in bleaching teeth, 528 

clamps, 196 

holders, 197 

ligatures, 196 

napkins, 198 

nausea, 200 

placement, 195 

punching, 194 

quality of rubber, 192 

sandarac or dammar varnish for •* 
securing, 196 

sterilization, 119 

supporter, 197 

svncope, 200 

use, 192 
Rubber and gutta-percha, properties, 310 



S 



Saliva, ejector, 191 

question of antiseptic action, 118 
role in tartar formation, 480 
Salol in filling pulp canals in deciduous 
teeth, 681 
for root canal filling, 458 
Scalers, 135 
Scaling, 135 

teeth, 486 
Schreier's kalium-natnum paste in bleach- 
ing teeth, 536 
Scorbutus, differential diagnosis from 

pyorrhea, 500 
Sensitive dentin, treatment, 146. See, 

also Dentin. 
Separation, counteracting soreness from, 
144 
gradual, immediate, or forcible, 140 
with base-plate gutta-percha, 

143 
with cork, 141 
with cotton, 140 
with elastic rubber, 142 
with linen tape, 141 
with wood, 141 
immediate or forcible, 143 
maintaining, 142 
necessary caution in, 142 
Separators, Capwell's "single-bow," 144 
Perry's, 143 
sterilization, 121 
Septicemia from abscess, 438, 455 

treatment, 445 
Silk floss for examining teeth, 138 
Silver iodid in pyorrhea alveolaris, for- 
mula, 507 
nitrate for cavity lining, 322 
for sensitive dentin, 151 
in treating deciduous teeth, 669 
Sinus, maxillary, infection, 571 
Sodium dioxid for bleaching teeth, 536 
Soldering in orthodontia, 757 



INDEX 



931 



Somnoform, 150 

Splinting loose teeth in pyorrhea, 508 
Square arch, 19 

Stains in teeth, from metallic salts, 
bleaching methods, 542. See also Dis- 
coloration. 
Sterilization, agents used, 128 
hands, 133 
instruments, 120 
by boiling, 131 
Sterilizers, boiling water, 133 
Downie's steam, 122 
Scherings' formalin, 130 
Sterilizing solution, 122 
Stratification bands in enamel, 69 
Sulcus, 173 
Sulfur dioxid for bleaching teeth, 53S 

Kirk's method, 539 
Sulfuric acid in scaling teeth, 491 
Supernumerary teeth, fourth molars, 49 
Suprarenin in local anesthesia. See 

Anesthesia. 
Swelling, facial, from acute apical abscess, 

treatment, 445 
Syncope from rubber dam, 200 

treatment, 400 
Syphilis contracted through extraction, 
125 
potassium iodid in acute apical ab- 
scess complicated with, 441 
Syringes, compound pressure, for cocain 
analgesia of dentin, 148 
electric warm air, 147 
Farrar's alveolar abscess, 444 
hot-air, 146 

hypodermic, for local anesthesia, 634 
for pressure anesthesia, 643 



Tartar, action on gingival tissues, 485 

in betel nut chewers, 481 

chemical nature, 474 

favorite locations, 476 

formation, role of saliva in, 480 

nature of composition, 479 

physical characteristics, 475 

as predisposing cause of pyorrhea 
alveolaris. See Pyorrhea. 

removal, 486 

serumal, in pyorrhea alveolaris, 503 

solvents for, 491 

subgingival, 484 
Tartasol, Head's, 492 
Teeth, anterior, selection of filling ma- 
terials for, 329 

apposition, 21 

articulation, normal, 22 

comparative anatomy, 57 

deciduous, management. See De- 
ciduous teeth. _ 

examination preliminary to opera- 
tion, 135 

forms, 18 

genesis, 18 
variations, 53 

functions, 18 



Teeth, incompleteness of development, 53 
influence on physiognomy, 873 
number and classes, 22 
occlusion, 20. See also Occlusion, 
pathological lesions, 55 
permanent, loss of, a cause of mal- 
occlusion, 724 
regulating. See Orthodontia, 
relations of physiognomy to the 

saving and extraction of, 893 
reversion to primitive types, 53 
scaling, 135 
separating, 140 

supernumerary, a cause of mal- 
occlusion, 724 
tardy eruption, a cause of malocclu- 
sion, 724 
temperamental impress in, 54 
temporary. See Deciduous teeth, 
tissues, 59 
the tuberculate, 34 
Temperamental impress in teeth, 54 
Temporary stopping, 318 

Gilbert's, in rilling deciduous 
teeth, 676 
Thermal shock in pulps, 392, 395 
Thumb sucking a cause of malocclusion, 

724 
Thymol and cement for pulp capping, 

394 
Tin and its combinations, 319 
for fillings, 201, 226 
foil fillings, 248 

and amalgam fillings, 321 
formation of cushions from, 248 
and gold fillings, 239, 249, 

321 
indications for, 320 
preservative qualities, 320 
shavings, 227 
Tomes, fibers of, 90 

granular layer of, 87 
Tongue biting, a cause of malocclusion, 
725 
pressure in occlusion, 699 
Tonics for hemophiliacs, 610 
Tonsils, enlarged faucial, a cause of 

malocclusion, 721 
Tooth movement. See Orthodontia. 
Toothache in children, treatment, 668 
Toxemia from apical abscess, 452 
Traction bar in orthodontia, 750 

screws in orthodontia, 749 
Transplantation of teeth, antiseptic pre- 
cautions in, 127. See also Plan- 
tation, 
indications for, 650 
terminology, 646 
Trephines for abscess treatment, 442 
Trichloracetic acid in scaling teeth, 

491 
Trimmers, gingival margin, 162 

gutta-percha, 316 
Tuberculosis, prevention by oral anti- 
sepsis, 125 
Tumors, rhomboid infiltration anesthesia 

for removal, 644 
Types of teeth, 18 



932 



IXDEX 



Vaccine therapy in oral infection, 509 
isolating bacteria for, 511 
method of making inoculation, 517 

Vaccines, preparation, 511 

V-arch, rounded, 20 

Varnishes for cavity lining, 322 

Vertebrates, teeth in, 17, 30, 34 



Wax, Taggart's automatic apparatus, 
379 

model for cast inlay. See Inlay. 

for root canal filling, 458 

treatment, 371 
Weaver pressure syringe, 149 
Weil, layer of, 91 
Wheels for cavity preparation, 164 
Wounds, treatment to prevent infection, 
127 



W 



Wax for casting, automatic electric Zinc chlorid for sensitive dentin, 151 
heater for softening, 372 oxy chlorid. See Cements, 

burning out, 379 oxyphosphate. See Cements. 

Taggart's, 367 phosphates. See Cements. 



